A United Nations human rights investigator says the Australian government is becoming increasingly secretive through a range of new laws, including a gag on officials speaking out about conditions at an Australia-run immigration camp in Nauru.

Michel Forst, the U.N.'s Special Rapporteur on human rights defenders, recommended Tuesday that Australia review its secrecy laws, including the "stifling" Border Force Act, to remove provisions that contravene human rights principles.

The Attorney-General's Department said Forst did not present a balanced view, but that the government would consider his recommendations.

Australian doctors have initiated a court challenge to the Border Force Act, which they argue gags them from speaking publicly about child abuse and other threats to asylum seekers and refugees held in the Pacific atoll nation of Nauru.