Tony Abbott insisted on providing a character reference for a Catholic priest later struck off the clergy list by the Vatican following a child abuse case, the former priest says.
John Gerard Nestor, who attended Sydney's St Patrick's Seminary with Mr Abbott in the 1980s, was a priest in the Wollongong diocese in NSW when he was charged with the indecent assault of a 15-year-old altar boy in 1991.
Mr Abbott, who in 1997 was a parliamentary secretary in the Howard government, later provided a character reference in court for then Father Nestor, describing him as "a beacon of humanity".
While a Wollongong magistrate found Fr Nestor guilty and sentenced him to jail, he won an appeal against the conviction in October 1997.
But the Catholic church never allowed him to return to ministry and about five years ago he was struck off the clergy list, or "laicised", by the Vatican after lengthy inquiries.
In a letter sent to the Wollongong diocese in 2009, the Vatican said it had "grave reasons" for making the decision.
Mr Nestor said at his home in rural NSW that Mr Abbott agreed to provide the character reference in 1997 after being approached by his barrister.
"When the lawyer approached Tony Abbott, he said 'Look, I know you're a parliamentary secretary and you may feel that because of your position you don't want to get involved in this case'.
"Tony said 'No, I'm coming down'. He insisted on coming down and giving the reference, because he's a man of integrity."
Mr Nestor said while he was "grateful" for Mr Abbott's reference, he did not believe it influenced the quashing of his conviction.
"The magistrate took no notice of it at all, or the other three [references].
"I think he would do the same thing if I was Joe Blogs, because he's a man of great integrity."
Mr Nestor said he wasn't "great friends" with Mr Abbott.
"He knew me well enough to make that statement, but that doesn't imply that he was my closest friend.
"His entire character reference related to 1984. He didn't say anything about my character at the time [of the case].
"He said 'This was the way he was at the seminary'.
" ... his insistence once he found out about [the case] ... says something about his character."
The two had become friends at the Manly seminary studying to become priests in the 80s, but their life paths diverged sharply. While Mr Abbott decided the priesthood wasn't for him, Mr Nestor started work at the Catholic Education Office in Wollongong.