Former judge skeptical of religious review

A former High Court judge fears the separation of church and state is at risk in Australia, as he raises concerns about the delayed release of a report into religious freedoms.

Justice Michael Kirby believes it "unusual" a review authored by former Liberal minister Phillip Ruddock was handed to the federal government in May but is yet to be published.

"That's a long time in Australian politics - we've lost another prime minister in that time," he told ABC radio on Thursday evening.

"The mind gets a bit suspicious."

The government has signalled it will released the report when there is legislation to accompany it.

Justice Kirby said secular members of the community were concerned something was being "cooked up" to give more power - or maybe even more money - to religious organisations.

"We've got to be careful about that," he said.

Justice Kirby, an Anglican, describes secularism as one of the greatest gifts of the British to constitutionalism.

He describes the principle as a society's respect for people of all religions or no religion.

"This is a really important gift that is a little bit at risk in the United States of America but there they've got constitutional protections for it," Justice Kirby said.

He believes secularism is at even greater risk in Australia.

"Our protections in the constitution have been interpreted very narrowly and therefore we're really at risk," Justice Kirby said.

"I think we've got to be very alert to the benefits of secularism for all of us, including people of faith."

Justice Kirby warned it would be "opening a nest of vipers" to wind back existing anti-discrimination laws and increase religious freedom protections for faith-based organisations.

He also raised concerns about some of the recent comments Prime Minister Scott Morrison has made about gay conversion therapy and the Safe Schools program.

Justice Kirby said it was good for Mr Morrison to say he loved all Australians including the LGBTIQ community.

However he is alarmed by the prime minister saying his "skin curled" when he learned children in public schools were being educated to respect people of diverse sexuality.

"Diverse sexuality is just part of science and part of our nature," Justice Kirby said.