The Corrections Minister is coming under more pressure over just when he knew about allegations a prisoner at the privately run Mt Eden Prison had been dropped from a balcony.

Sam Lotu-Iiga said he only heard those rumours in the past week but a transcript of a select committee hearing revealed the matter was first raised with him last month.

Photo: RNZ / Alexander Robertson

Labour's corrections spokesperson Kelvin Davis said the prisoner - Nicholas Evans - subsequently died.

Mr Davis said Mr Lotu-Iiga ignored warnings about the matter and should resign.

Mr Lotu-Iiga told reporters this afternoon he only heard recently about allegations prisoners at Mt Eden were being dropped from balconies.

"Well you know I've heard the allegations in the past week... well, from Kelvin. Kelvin said he's been chucked off," he said.

Photo: RNZ / Alexander Robertson

Prime Minister John Key said he still had confidence in Mr Lotu-Iiga but signalled he would not be happy if the minister knew about people being dropped off balconies earlier and had done nothing about it.

"Of course I'd be concerned. If that had really happened - I understand [dropping] is not a term people understand or know," Mr Key said.

"But that is a situation where people would become potentially very seriously injured, if not fatally injured. I mean, that's a very serious matter."

Mr Davis said there was plenty of evidence the minister had known about the practice for at least a month.

"News reports from June, the select committee transcript from June and it's all there. It has happened and the minister has done nothing about it," Mr Davis said.

The transcript from last month's law and order select committee hearing does confirm Mr Lotu-Iiga was told about the matter then.

In the transcript Mr Davis said: "There's the guy that passed away recently. Apparently he had a ruptured lung. I've asked, how do you get a ruptured lung?

"It's often from high-impact collision and there's accusations that prisoners have been thrown off balconies and they're getting transferred out of Mt Eden Correctional Facility.

"And I'm getting this on good measure, Minister."

Mr Lotu-Iiga replied: "Well you're getting hearsay-type representations but the reason I point these figures out is we're talking about serious prisoner-on-staff and prisoner-on-prisoner. The numbers from Mt Eden are actually in line with other prisons."

Late in the day, Mr Lotu-Iiga said he could now recall the matter being raised at the select committee.

But he said there had been no suggestions throwing prisoners off balconies was a widespread practice.

Earlier, Mr Lotu-Iiga said people should not jump to conclusions about the death of a prisoner.

"I think it's unwise and I said this to Kelvin straight - for us to speculate and comment on a death that requires the coroner to intervene, that requires the chief inspectorate to gather all the facts and make some conclusions.

"If then, when they gather those facts, it needs to be referred to the police then it will be referred to the police. But I don't think it's wise and I don't think it's prudent to make that speculation at this point," he said.

But Mr Davis said the minister and Serco, the company which runs Mt Eden, had to take responsibility.

"Prisoner Evans was, was injured before he was shipped off to Ngawha and that's unacceptable as well and it raises the question which prison is having to account for the injuries - and my suspicion is that Serco is shipping them out so that their books look clean."

Mr Davis said he believed a number of problems at Mt Eden Prison were not being reported because, under its contract, Serco would lose money as a result.

Despite the problems, however, Mr Key still supports privately run prisons.

And, for the moment, his embattled Corrections Minister Sam Lotu-Iiga.