Federal government frontbencher Simon Birmingham does not believe one of his Cabinet colleagues should step aside, after a letter accused an unnamed government Minister of allegedly raping a woman more than 30 years ago.

The ABC’s Four Corners yesterday revealed Australian Federal Police had been notified of an anonymous letter sent to Prime Minister Scott Morrison detailing an alleged historical rape by a Cabinet minister in the federal government.

The letter requests urgent action be taken by the Prime Minister to investigate the alleged rape, which occurred in 1988 before the accused man entered politics.

Senator Birmingham was repeatedly asked at a press conference in Adelaide on Saturday whether the accused man should be identified to protect the rest of the government.

“Everybody is entitled to natural justice and it’s important to back the police to do their job,” he said.

“We back the police to do their job in this and every other instance.

“I don’t wish to see anybody lose their rights to natural justice.”

-more to come