The long-running inquiry into phone hacking has concluded after prosecutors announced no charges would be brought over remaining allegations.
Former Daily Mirror editor Piers Morgan, who was previously interviewed under caution, vowed to get "spectacularly drunk" after being told he will face no further action.
The Crown Prosecution Service concluded there is "insufficient evidence to provide a realistic prospect of a conviction" in relation to corporate liability at News Group Newspapers, the company that published the now defunct News of the World, for alleged phone hacking.
The same decision was reached in relation to 10 journalists who worked at Mirror Group Newspapers.
It signals the end of the CPS's involvement in phone hacking investigations, which were launched in 2011 in the wake of revelations about the practice at the NotW.
A Scotland Yard spokeswoman confirmed: " Police investigations into phone hacking have concluded."
Morgan, 50, said on Twitter: " I 've today been informed by CPS that no further action will be taken against me re Met Police phone hacking investigation.
"As I've said since the investigation began four years ago, I've never hacked a phone and nor have I ever told anybody to hack a phone.
"Thanks to all my family & friends, and kind people on here, for all their support. It was greatly appreciated."
He added: "I'm now going to get spectacularly drunk. Happy Christmas."
Director of Public Prosecutions Alison Saunders said the CPS has "looked in great detail" at "comprehensive" files submitted by the police.
She added: "After a thorough analysis, we have decided there is insufficient evidence to provide a realistic prospect of a conviction and therefore no further action will be taken in any of these cases.
"There has been considerable public concern about phone hacking and invasion of privacy.
"Over the past three years, we have brought 12 prosecutions and secured nine convictions for these serious offences. These decisions bring the CPS's involvement in current investigations into phone hacking to a close."
Those convicted include former NotW editor and Downing Street spin doctor Andy Coulson.
Three people were acquitted, including Mr Coulson's predecessor at the paper Rebekah Brooks, while several others were arrested before being told they would face no further action.
Operation Weeting, the central phone hacking inquiry launched by Scotland Yard in January 2011, had cost £22.8m as of the end of last month.
A spokeswoman for News UK, of which NGN is a subsidiary, welcomed the decision.
"Long ago, we apologised for the conduct that occurred, immediately took steps to pay compensation to those affected, and updated and instituted substantial reforms in our business to ensure our governance is second to none," she said.
"Following a thorough and exhaustive investigation, and after many long trials, inquiries and proceedings, this matter has been concluded and the right decision has been taken."
Files relating to 10 journalists were considered under Operation Golding, an investigation into allegations of phone hacking at Mirror Group Newspapers, but it was determined there was insufficient evidence against any individual suspect to provide a realistic prospect of conviction.
Following the developments, campaign group Hacked Off said it was "surprised and disappointed".
Assistant Commissioner Patricia Gallan of the Met Police said after the conclusion of Operation Weeting: "Those that suffered from having their phones hacked included those who were already victims of crime, and all were greatly affected by the intrusion into their personal lives and the mistrust and paranoia it caused.
"The police investigations into allegations of phone hacking are now complete. I would like to thank the detectives and staff who worked tirelessly on Operation Weeting, gathering, without fear or favour, the evidence which resulted in the conviction of eight journalists and one private investigator; for the exceptional support they provided to the victims and witnesses."