The Australian government has accused the charity, Save The Children, of fabricating stories about abuse at Canberra's detention centre on Nauru.
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 border protection policies.
Mr Morrison says the matter will be probed.
"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, says she welcomes the probe after she had demanded the immigration department investigate allegations of sexual exploitation of women and children at the Nauru camp.
"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 messenger and then drops it all to his favourite home town paper."
Protest at Nauru family residential compound - 27 September, 2014. Photo: Supplied
