New Immigration Minister Brendan O'Connor says he will visit the Nauru detention centre to personally investigate claims of self-harm and rape.

An Australian nurse who worked in the centre last year says she saw several people attempt suicide and heard stories of gang rapes at the centre.

Mr O'Connor says the accounts are disturbing.

He says the Government will work with the United Nations, Nauru and Papua New Guinea to prevent such things happening.

"I will be visiting both Manus [Island] processing centre and Nauru as soon as I possibly can so I can actually be properly briefed and see for myself exactly the situation in those centres."

Marianne Evers, a trained counsellor and a nurse with more than 40 years experience, signed up for a six-week stint at Nauru last November but quit after three weeks.

Around the time she resigned, two mental health workers also quit.

Ms Evers has worked at the Curtin, Yongah Hill and Darwin detention centres and says they are all difficult places to work.

But she says Nauru is by far the worst.

"I actually liken it to a concentration camp, but the Australians don't have the guts to kill these people and put them out of their misery," she said.

"There is absolutely nothing to do. There are no trees. There is no grass. There is not even that many birds there. So we live in that heat without air conditioning in tents.

"It is just desperation that I can't get out of my head. Of all of them. I have seen people crawling on the floor like animals [saying] please let me die. These pictures don't leave you."

There are around 400 single men in the detention centre, around half of them Sri Lankan.

The veteran nurse says she witnessed and dealt with cases of self-harm and attempted suicide.

"I saw people hang themselves. I think in the three weeks I was there, there were three or four hangings that I witnessed and I don't think that has stopped since. These people are desperate," she said.

Ms Evers says medical staff told her there were other disturbing incidents at the centre, such as gang rapes.

"I have never actually witnessed that but there have been rapes, as I have heard," she said.

'A disgrace'

But that is news to the Immigration Department, which says it wants all allegations of criminality reported to local authorities.

DIAC spokesman Sandi Logan says no allegations of rape have been raised at Nauru since the first asylum seekers were sent there five months ago.

"A nurse who was employed on contract for a short period of time on Nauru, who has a professional - if not a moral - obligation to report a serious allegation like this to the relevant authority and has not done so and is instead airing them on a TV program," he said.

"I question why this person has waited until now if in fact there's anything to this claim."

He also hit back at Ms Evers's comparison of Nauru to a concentration camp, labelling her comments "a disgrace".

"I think invoking concentration camps is a disgrace to be quite honest with you," he said.

"I don't think anyone should be throwing terms like concentration camp around with such abandon.

"We understand that the temporary facility, part of which is transitioning to a permanent facility at the Nauru regional processing centre, is on a country that is hot and is humid, but the level of care is being provided for the 415 men currently there is a very good level of care.

"It is important that we recognise this is consistent with the policy that the Government has announced around no advantage."

'By far the worst'

It has been five months since the first asylum seekers were sent to Nauru, but immigration processing is still yet to begin.

Alex Pagliaro from Amnesty International says a sense of uncertainty and despair pervades the centre.

"I have been to most of the remote detention centres and Nauru is in by far the worst condition that I have seen Australia hold asylum seekers in," she said.

"[We're not] mental-health professionals, but on the face of it ... they were in various stages of mental distress.

"They were confused about why they had been sent to this place; they were confused about how long they would be there; and they were distraught that no-one could give them any answers about the questions that were so vital to their lives."

The Immigration Department says the timetable to set up immigration processing is a matter for the Nauruan government.

By speaking out, Ms Evers is breaking a confidentiality contract and she knows she will never work for the Immigration Department again.

But she says that she felt so strongly about the conditions at Nauru that she had to break the contract.

"I would not be human if I did not breach it," she said. "You can't treat people like that. You cannot."