The erosion of fundamental freedoms and overreach of ministerial discretion is leaving Australia increasingly isolated from international community standards, the president of the Human Rights Commission, Professor Gillian Triggs has warned.

"Gone are the days when we could say, 'How dare Saudi Arabia, Qatar, Libya criticise Australia's human rights record," Professor Triggs said in a speech on Australia's asylum seekers and refugee policies.

"Now we are attracting the concern of our traditional allies - the UK, Canada, the US - and powerful allies in Asia such as China, Japan and Indonesia."

In an impassioned address, Professor Triggs called for the end of offshore detention, branding it "illegal, eye-wateringly expensive and unsustainable in the longer term".