Northern Ireland's only high security jail is not "broken", the new governor has insisted.
Phil Wragg has been running Maghaberry prison since July and claims "good progress" has been made on improving the facility recently branded in the Stormont Assembly as "not fit for purpose".
He said: "I was asked when I arrived at Maghaberry whether I thought it was broken.
"Clearly my opinion is absolutely no, Maghaberry is not broken."
Mr Wragg is a former governor of HMP Belmarsh which housed some of the UK's most notorious criminals including gangsters, drug traffickers and Islamic extremists.
His comments were made during a briefing for MLAs on the justice scrutiny committee at Parliament Buildings.
As well as life sentence prisoners, rapists and armed robbers, Maghaberry includes segregated wings for both dissident republican and loyalist paramilitary inmates.
Problem with drugs and overcrowding have been highlighted in a number of criminal justice inspection while i ssues with low staff morale have also been well documented.
Mr Wragg added: "The establishment is complex.
"It has to deal with a number of different types of prisoner under one roof without the ability to move people who provide us with a level of concern to other establishments."
It was also revealed that a new staff canteen where inmates prepare the meals had been widely welcomed by rank and file officers.
Mr Wragg said: "It is such a resounding success that we are having to expand the facility because we cannot fit the number of people (in) that want to use it.
"That provides an environment for staff to be able to go and have good quality food at a good quality price and have time to have a bit of a chat to their colleagues.
"And the important thing is there are prisoners doing the catering. There are prisoners who are earning a qualification by working in that environment.
"The challenges where we had prison staff saying they would not work in an environment where food was being provided by prisoners has disappeared. It doesn't exist any more.
"So, it is a win-win situation."
Mandatory drug testing has also been stepped up with 110 carried out over the last two weeks.
"We are hot on drugs. We are hot on testing for drugs. We want to know exactly what the level of drug non compliance is within the establishment," said Mr Wragg.
Meanwhile, Sue McAllister, Northern Ireland Prison Service director general, said there was a need to reconfigure Maghaberry with a dedicated high security facility.
MLAs also heard that a reduction in staff sickness levels and the deployment of extra officers on the prison landings meant inmates were not subjected to so many lock-downs.
"Now they are having to say to prisoners 'you are locked up one night this week' rather than previously 'you will be out one night this week'," said Ms McAllister.
Sinn Fein's Raymond McCartney acknowledged that Maghaberry's size and make-up meant it was difficult to manage.
Edwin Poots from the DUP, whose Lagan Valley constituency takes in Maghaberry, described it as a "controversial" prison and claimed the high turnover of senior staff was unhelpful.
Alliance Party MLA Stewart Dickson said he had detected a more positive atmosphere during a visit to Maghaberry in the summer.
He said: "I could feel that there was a very different and much more positive atmosphere among the staff that I met and indeed the demeanour of prisoners in prison as well."