"Two things are shocking. It's shocking that fighting is going on inside the prison, it is also shocking that there are mobile phones in the prison," he said.
Mr Soames added he did not think Mt Eden was the only prison where mobile phones had been smuggled into, and said: "We live in a real world here ...if you're going to put a lot of, often very violent, men together, there is fighting. I don't justify it, I don't condone it. I'm very worried about the idea of the existence of a fight club and clearly there's too much violence in prison."
The level of violence in the corrections facility had "dropped a lot" in recent years, he said, but had picked up again recently.
"One of our issues there is to find out why it is, and what we can do better to run that prison." Mr Soames said he was "responsible" for what goes on inside the corrections facility.
"You ask who's responsible, I am responsible. I am the chief executive of Serco, therefore the buck stops with me," he said.
"But I would say to the taxpayers of New Zealand that what the facts that we know show - and it may turn out that the reporting has been wrong and there's something going on - if the reporting has been correct, what the taxpayers had in New Zealand is a situation where one of the worst-rated prisons has become one of the best-rated prisons. It's been rated exceptional ... and it's also been done at a cost that is substantially lower."
Accusations that Serco was cooking its books in order to improve its ratings were "incredibly serious", Mr Soames said.
"The citizens of New Zealand, and our customers, have the right to expect that the numbers and the issues that we are reporting to them are correct," he said.
"Now, when I say correct I don't mean completely error free, but that we have been properly reporting.
"Personally, I want to get to the bottom of these allegations. Either Mt Eden has improved greatly under our [direction] or it hasn't. If it has then I think Serco should be praised and say, 'well done Serco', if it hasn't then we'll have to bear the consequences of it.
"I'm completely clear about this, and people have to be able to trust that we are reporting what is actually going on." The company wanted to prove itself trustworthy, Mr Soames said, as it was interested in running other Government contracts, in particular the rail network, state housing "and other opportunities".
"We are committed to New Zealand. We wish to be a good citizen here. We are active in the area of Government services and part of the reason I'm here is to make sure that we are dealing and responding appropriately here."
In a statement issued to The Nation, Mr Lotu-Iiga confirmed he had met with Mr Soames at the Serco boss' request. He was not prepared to go into details of the meeting, Mr Lotu-Iiga told the programme, but said: "Mr Soames will have left with a clear idea of my expectations and the expectations of the New Zealand public about the future performance of his company, and under no illusions about my feelings on its performance so far."
- NZME.