The United Nations has called for the Abbott government to “respect the rule of law” after it accused a damning inquiry into child detention by the Australian Human Rights Commission (AHRC) of bias.

In a statement to Fairfax, the UN’s Working Group on Arbitrary Detention threw its support behind AHRC president Gillian Triggs, urging the government to respect her “personal authority” and “high reputation”.

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The comments come after Prime Minister Tony Abbott slammed the AHRC inquiry as “blatantly partisan” and accused the Ms Triggs of conducting a “transparent stitch-up”.

The Forgotten Children report found more than 30 incidents of children in immigration detention being sexually assaulted, and called for a royal commission.

Fairfax media revealed the Abbott government sought the resignation of Ms Triggs two weeks before the AHRC released its report, allegedly telling her “some other opportunity” would be made available.

The UN said the commission’s statements were “highly authoritative” and “reliable”, and urged the government to respect the findings.

In an interview with 3AW radio following the report’s release, Mr Abbott said the government should be congratulated for stopping the flow of illegal arrivals.

“I reckon the human rights commission ought to be sending a note of congratulations to Scott Morrison saying well done, mate,” Mr Abbott said.

“The human rights commission ought to be ashamed of itself.”

Former Liberal Prime Minister Malcolm Fraser slammed Mr Abbott’s reaction to the report, calling him a “bully-boy”.

“If the Government had wanted to handle the matter sensibly, they would have said they recognise there have been abuses,” Mr Fraser told ABC radio.

“Instead of doing that, they’ve chosen to attack the commission as a body and to attack the chairperson in particular, which I think is outrageous.”

“If anyone should resign, the government should resign,” he said.