Mr Ayers was born in 1933. He was an education and parole officer in Melbourne's Pentridge prison before rising through the ranks and moving to Canberra as the ACT Director of Welfare in 1967.

After stints as head of the departments of Aboriginal affairs and social security, he became defence secretary in 1988, a role he held for a record 10 years.

Fred Chaney, former deputy leader of the Liberal Party, said in a 1993 profile of Mr Ayers that, "Tony is everything I would like the Australian Public Service to be."

He earned a reputation as an extraordinary people manager and advocate for departmental secretaries, and would call himself their "shop steward".

The job of secretary was, in his opinion, to bring on at least two people who were better than yourself. He was a renowned spotter and developer of talent.

"He was probably the best people manager the service has seen in the last 50 years," his close friend and professor of public policy at the Australian National University, Andrew Podger, said.

"He was a mentor to many, many public servants and for a time he was doing more with career management and succession management for the top of the public service than anybody else."

He was one of few secretaries at the time who headed departments under both Coalition and Labor governments, and advocated against the political cleansing of the public service after an election.

He disliked the concept of senior public servants "as political groupies attracted to the light of their own political party like a swarm of bogong moths."

He married and had four children, and was made an Officer of the Order of Australia in 1984. He died on Monday, April 11.