MPs suspended their questioning of Rupert Murdoch this afternoon after the media tycoon was hit in the face with a plate of shaving foam by a man shouting: "Greedy."
Mr Murdoch's wife Wendi and his son James jumped to his defence as the attack was launched as the final questions were being asked by MPs.
The hearing was suspended as a man wearing a checked shirt with what appeared to be foam splashed across his face was detained by police.
Mr Murdoch, 80, was apparently pelted with a plate of foam.
MP Chris Bryant condemned the attack in which he said the media mogul had the plate pushed into his face.
James Murdoch was in mid-sentence as the attacked was launched.
Wendi Murdoch, who had sat behind her husband throughout his appearance before the Commons Culture, Media and Sport Committee, appeared to strike back at the assailant in defence of her husband.
The hearing resumed ten minutes after the attack with Mr Murdoch now wearing shirt sleeves but apparently unharmed.
Eyewitnesses said a member of the audience sat at the back of the room stood up and walked around to the front where Mr Murdoch was giving evidence and threw what appeared to be a paper plate covered in shaving foam at him.
As the protester was being taken from the room, Mr Murdoch's wife threw the empty paper plate at him.
The session was then suspended.
As the man was being led away in handcuffs escorted by a single police officer, he refused to give his name, saying: "As Mr Murdoch himself said, I'm afraid I cannot comment on an ongoing police investigation."
His shirt and hair was covered in what appeared to be white shaving foam.
Earlier in the proceedings, a contrite Rupert Murdoch told MPs: "This is the most humble day of my life".
Sitting alongside his son, James, the 80-year-old media mogul said that he was "more than prepared" to answer the questions of the Commons Culture, Media and Sport Committee into the phone hacking scandal.
The start of the keenly-awaited hearing in the Wilson Room of Portcullis House was briefly disrupted as some protesters were removed.
James Murdoch, News Corp's deputy chief operating officer, opened by saying how sorry he and his father were to the victims in the News of the World phone-hacking scandal.
"It is a matter of great regret of mine, my father's and everyone at News Corporation. These actions do not live up to the standards our company aspires to everywhere around the world," he said.
"It is our determination both to put things right, make sure these things don't happen again, and to be the company that I know that we have always aspired to be."
James Murdoch told the committee the company acted "swiftly" as soon as it became aware of fresh evidence over phone hacking following a series of civil actions in 2010, particularly the case involving actress Sienna Miller.
It became apparent that more people than originally believed were victims of the practice, he added.
Mr Murdoch Jnr said: "Subsequent to our discovery of that information in one of these civil trials at the end of 2010, which I believe was the Sienna Miller case, the company immediately went to look at additional records around the individual involved, the company alerted the police and restarted, on that basis, the investigation that is now under way."
He said the company had apologised "unreservedly, which I repeat today," to phone hacking victims.
He added: "The company acted as swiftly and transparently as possible."
Asked by Labour MP Tom Watson whether he had been "misled" by senior employees, Mr Murdoch senior replied: "Clearly."
Mr Watson pointed out that former News International chief executive Rebekah Brooks admitted in 2003 that police were paid for information.
Mr Murdoch senior said: "I am now aware of that, I was not aware at the time. I'm also aware that she amended that considerably very quickly afterwards."
Mr Watson said: "I think she amended it seven or eight years afterwards but did you or anyone else in your organisation investigate it at the time?"
Mr Murdoch replied: "No. I didn't know of it.
"I'm sorry, if I can just say something and this is not as an excuse, maybe it's an explanation of my laxity.
"The News of the World is less than 1% of our company. I employ 53,000 people around the world who are proud and great and ethical and distinguished people, professionals in their work.
"I'm spread watching and appointing people whom I trust to run those divisions."
James Murdoch told the committee: "I can tell you that the critical new facts as I saw them and the company saw them really emerged in the production of documentary information or evidence in these civil trials at the end of 2010.
"And the duration from 2007 to 2010, and the length of time it took for that to come clear and for that real evidence to be there, is a matter of deep frustration - I have to tell you I sympathise with the frustration of this committee.
"It's a matter of real regret that the facts could not emerge and could not be gotten to, to my understanding, faster."
He was asked by committee chair John Whittingdale which News of the World staff, apart from Clive Goodman, were involved in phone hacking.
"There have been a number of arrests of former News of the World employees," Mr Murdoch said.
"These are matters for current criminal investigations and I think understandably it's difficult for me to comment in particular on some of those individuals."
Asked why he had not sacked News of the World chief reporter Neville Thurlbeck after the Max Mosley case, when the judge found he had blackmailed two prostitutes involved, Rupert Murdoch replied: "I have never heard of him."
He acknowledged that a review of News International emails by former director of public prosecutions Lord Macdonald's review found evidence of "indirect hacking, breaches of national security and evidence of serious crime".
"He did indeed," he said.
James Murdoch said his father was told of an out-of-court settlement with Professional Footballers' Association chief executive Gordon Taylor for phone hacking only after it became public in 2009.
"Please understand that an out-of-court settlement of civil claim of that nature and of that quantum is something that normally in a company of our size the responsible executives in the country would be authorised to make," he said.
"It is below the approval thresholds that would have to go to my father as chairman and chief executive of the global companies."
Mr Watson asked Rupert Murdoch when he became aware that criminality was "endemic" at the News of the World.
"Endemic is a very hard, a very wide ranging word," he replied. "I also have to be very careful not to prejudice the course of justice that is taking place now.
"That that has been disclosed I became aware of as it became apparent.
"I was absolutely shocked, appalled and ashamed when I heard about the Milly Dowler case only two weeks ago."
Questioned about the 200 journalists who lost their jobs when the News of the World was closed down, Mr Murdoch senior replied: "When a company closes down it is natural for people to lose their jobs."
He said they had tried to secure employment for those people in other divisions of the company.
Explaining why the newspaper was shut down, he said: "We felt ashamed at what happened. We had broken our trust with our readers."
At one point James Murdoch stepped in to request that questions were directed to him rather than his father.
"Mr Watson and Mr Chairman, I think it would be helpful to the committee if you would like to go through any of the particular detail about why decisions were made by the management team of News International and the precise chronology it would be more helpful if I could answer those questions as the Chief Executive of the regional business across Europe.
"I have somewhat more proximity to it."
But Mr Watson replied: "Your father is responsible for corporate governance and serious wrongdoing has been brought about in the company.
"It is revealing in itself what he does not know and what executives chose not to tell him."
Rupert Murdoch denied that he was ultimately responsible for the "fiasco".
Asked by Labour's Jim Sheridan who was, Mr Murdoch replied: "The people that I trusted and then, maybe, the people they trusted."
He said he had worked with Les Hinton, who quit his role as chief executive officer of Dow Jones and Co last week, adding "I would trust him with my life."
Mr Murdoch revealed he had been invited to have a cup of tea as a thank you by the Prime Minister within days of the general election last year.
He admitted he had entered No 10 through the back door after being asked to, he believed, to avoid photographers.
"I just did what I was told," he added.
"That's the choice of the Prime Minister, or their staff, or whoever does these things.
"I was asked would I please come in through the back door.
"I was invited within days (of the election) to have a cup of tea to be thanked for the support by Mr Cameron.
"No other conversation took place."
He said he was also invited by former prime minister Gordon Brown "many times" and had also gone in through the back door.
He denied imposing any "preconditions" on party leaders before giving them support.
Mr Murdoch insisted he knew of no evidence that the phones of 9/11 victims had been hacked but "absolutely" would launch a full investigation if any revelations came to light.
Conservative MP Therese Coffey asked who decided that the News of the World should be shut down.
Mr Murdoch senior replied: "It was a result of a discussion between my son and I and senior executives and Ms Brooks one morning.
"We called the board of News Corporation, the whole board, to seek their agreement."
Pressed on whether it was a commercial decision, he replied: "Far from it."
James Murdoch was asked for more information on Mr Taylor's out-of-court settlement.
"The underlying interception was not a disputed fact," he said.
"It was the advice and the clear view of the company that, if litigated, the company was almost certain to lose that case."
The company was advised that it could lose between £500,000 and £1 million in legal expenses and damages if it went to court, he said.
"This was in the context of the first half of 2008 and this was my first real involvement with any of these issues, where there was no reason at the time to believe that the issue of these voicemail interceptions was anything but a settled matter and that it was in the past after the successful prosecution of the two individuals we discussed, as well as the resignation of the editor," he said.
Asked if he would rethink the way his papers presented stories, Rupert Murdoch said: "I am sure that there are headlines which can occasionally give offence but it is not intentional."
He added: "This doesn't take away from our apologies or our blame, but this country does benefit greatly from a competitive press and therefore having a very transparent society.
"That is sometimes very inconvenient to people, but I think we are better and stronger for it.
James Murdoch said there was a need in the UK press to think "more forcefully and more thoughtfully about our journalistic ethics".
Both men played down the suggestion that they were planning to open a new Sunday tabloid to replace the News of the World.
"We have made no decision on that," Rupert Murdoch said. His son added: "I think we leave all those options open. That is not the company's priority now."
James Murdoch said it was only as result of civil actions that it became apparent that the practice of phone hacking extended beyond former royal reporter Clive Goodman and private detective Glenn Mulcaire, who were jailed in 2007.
"At the end of 2010 the presentation of evidence that had not been in our possession previously from this civil litigation that widened the circle definitively - or at least made it very apparent that this was very likely that the circle was wider than the two individuals, Mr Goodman and Mr Mulcaire," he said.
He said that he had been advised by the News of the World's then editor Colin Myler and chief lawyer Tom Crone to settle Mr Taylor's claim for damages out of court.
"Their advice was that in the absence of new evidence, that this was simply a matter to do with events that had come to light in 2007 in the criminal trial before and before I was there and that this was a matter in the past," he said.
"The police as well had closed their case and said there is no new evidence here."
James Murdoch said they had taken advice on the "context of the setting" of the committee.
"We were advised fundamentally to tell the truth and be as open and transparent as possible."
Mr Murdoch senior was asked how often he spoke to his newspaper editors.
"Very seldom," he said. "Sometimes I would ring the News of the World on a Saturday night to say have you got any news tonight. But it was just to keep in touch. I ring the editor of the Sunday Times nearly every Saturday night."
Mr Murdoch said he had to deal with a "multitude of issues" every day, and admitted he may have "lost sight" of the News of the World.
"The News of the World, perhaps I lost sight of. Maybe because it was so small in the general frame of our company," he said.
Asked to explain the scale of the reported £1 million payout to publicist Max Clifford over phone-hacking, Mr Murdoch senior replied: "Apparently there was a contract with Mr Clifford that was cancelled with Mr Coulson."
The comment was not clarified any further.
James Murdoch said the 2008 payout to Mr Taylor, believed to be around £600,000, was based on advice from legal counsel and took account of costs as well as damages. The view on the level of damages that could be due had changed after F1 boss Max Mosley was awarded £60,000 in damages in July 2008.
Asked why he had not accepted Ms Brooks' original offer to resign, Rupert Murdoch said: "Because I believed her and I trusted her and I do trust her."
Explaining why he eventually accepted it, he said: "In the event, she just insisted. She was at a point of extreme anguish."
Mr Murdoch said Mr Hinton had "sadly" offered to resign as he was in charge of News International at the height of the hacking abuse.
He refused to give details of the pay-off each will receive but said Mr Hinton's would "certainly be considerable" as it would include pension packages.
James Murdoch said commercial confidentiality agreements were part of the exit package but there was nothing that would "stop or inhibit" them from co-operating fully with investigations.
Mr Murdoch senior was asked how far he believed reporters should go in pursuit of a story.
"I think phone hacking is something quite different but I do believe that investigative journalism ... does lead to a more transparent and open society, inconvenient as that may be to many people," he said.
"And I think we are a better society because of it and I think we are a more open society than even the United States."
He added: "There is no excuse for breaking the law any time. There is an excuse, if I may say so, for all newspapers when they wish to campaign for a change in the law but never to break it."
Rupert and James Murdoch face questions before the panel of MPs under intense pressure from their own shareholders, who have seen the value of their stock fall by almost a fifth – 17.9 per cent – since it emerged that the murdered schoolgirl Millie Dowler had been among victims of the company's journalists. The answers of the Murdochs will also be analysed by a number of investigating bodies, including the media regulator Ofcom which is gathering evidence on whether News Corp is "fit and proper" to own a broadcasting licence in the UK, and the Serious Fraud Office.
The pair's evidence will be followed by that of Rebekah Brooks, who resigned her post as their chief executive at News International last week, before being arrested on Sunday by police investigating the hacking and illicit payments made to officers. Yesterday Brooks fought back. Her lawyer, Stephen Parkinson, hinted that his client would take steps to redress damage to her reputation. "Despite arresting her yesterday and conducting an interview process lasting nine hours, [the Metropolitan Police] put no allegations to her and showed her no documents connecting her with any crime. They will in due course have to give an account of their actions and in particular their decision to arrest her with the enormous reputational damage that this has involved."