The Chief Executive of the charity, Save The Children, has accused Australia's government of trying to "shoot the messenger" after Canberra accused the charity of fabricating stories about abuse at the asylum seeker detention centre on Nauru.
Earlier this week, asylum seekers alleged the sexual abuse of women and children and threats of rape by guards working at the centre.
However, the immigration minister, Scott Morrison, says he has received intelligence reports that service provider staff were engaged in a broader campaign with external advocates to cast doubt on its border protection policies.
The Immigration Department on Thursday night ordered 10 Save The Children staff to leave Nauru.
However, a statement from Scott Morrison's office says the removals don't relate to any suspected misconduct regarding sexual abuse or sexual misconduct.
Save The Children's Chief Executive, Paul Ronalds, says he rejects any suggestion his staff have in any way fabricated stories of abuse on Nauru.
Mr Ronalds says he has no idea what the government is alleging against his workers, and it appears to be a case of Canberra trying to shoot the messenger after it raised allegations of misconduct on Nauru.
"We raised our concerns around inappropriate behaviour by non-Save The Children service providers on the island to the department for the department to investigate. What this looks like is a case of the government wanting to shoot the messenger rather than investigate and take seriously the claims that our staff have made."
Meanwhile, Paul Ronalds says Save The Children will cooperate fully with an investigation announced by Mr Morrison on Friday into the abuse allegations.
Scott Morrison says the inquiry will probe the claims of sexual abuse, as well as the suggestions that the claims were made up.
"Today I announce that the Acting Secretary for the Department of Immigration and Border Protection has commissioned Mr Philip Moss to conduct an independent investigation into all of these matters. Mr Moss is formally as you know the Integrity Commissioner and former head of the Australian Commission for Law Enforcement Integrity."
The opposition Greens senator, Sarah Hanson-Young, has welcomed the probe, but she has reservations.
"What I am concerned about is that the Minister seems to be pre judging the investigation before it has even started. This is a Minister who blames the victim, shoots the messanger and then drops it all to his favourite home town paper."
Detainees on Nauru have been holding a series of protests over the past week, after Canberra signed a multi-million dollar resettlement deal with Cambodia.