Save the Children says its staff members in Nauru who were sacked by the Australian government have still not received an apology.
An Australian Senate inquiry into the conditions on Nauru, launched following the release of the Moss Review, has heard evidence from the centre's operator and security firm, as well as representatives from Save the Children.
Nine Save the Children staff were deported from the detention centre in October after a report claimed they had encouraged protests and self-harm as part of a wider campaign to embarrass the Australian government.
But the Moss Review, ordered by a former Immigration Minister Scott Morrison to investigate the matter, found the claims had no substance.
It instead confirmed cases of rape, sexual abuse of children and the sale of drugs for sexual favours with some staff.
Save the Children's chief executive, Paul Reynolds, told the inquiry into conditions at the Nauru camps that the staff were never given a chance to answer to the allegations.
"Reading through the Moss report findings and I was very interested when that was made available to us, the actual chain of events, and I would describe it more akin to Chinese whispers than any sort of serious evidence gathering exercise."
Centre's security defended
Wilson Security, which provides security at the Australian-run detention centre on Nauru, has defended its handling of the facility.
The company made an oral submission at a Senate inquiry into allegations of sexual abuse, violence and neglect at the camps yesterday.
Senator Kim Carr asked Wilson Security's executive general manager, John Rodgers, about allegations a woman had been raped by a cleaner while visiting a toilet at night.
KIM CARR: How is it that you are not able to maintain the security so that women cannot go to the toilet at night without fear of being assaulted?
JOHN RODGERS: Senator, I don't accept that we're not able to maintain the security there. In the execution of our contract, we have consistently exceeded the KPIs that have been set for us and I believe we have done a very professional job of managing the security at the centre.
Dutton labels inquiry a "witch hunt"
Australia's immigration minister has called the inquiry a witch hunt.
The minister, Peter Dutton, has accused the opposition Labor and Green parties of delaying proceedings to prevent the department from presenting its evidence, as it would have been an inconvenient truth for the parties' witch hunt.
He says the department will cooperate fully with the inquiry, but it should be seen as nothing more than a waste of time and taxpayers' money.
Mr Dutton says he has zero tolerance for criminal activity at detention centres, and the department has already made significant progress in implementing the recommendations of the Moss Review, which triggered the inquiry.