In this image made from video, Archbishop Philip Wilson, centre, heads to Newcastle Local Court, north of Sydney. Picture: Australian Broadcasting Corporation via AP

Canberra - An Australian archbishop, the most senior Catholic official in the world to be convicted of concealing child sexual abuse will be sentenced in July after a magistrate reserved his decision at a hearing on Tuesday.

Philip Wilson, 67, the Archbishop of Adelaide, South Australia, was found guilty last month of concealing the crimes of a paedophile priest in the 1970s in regional New South Wales.

Wilson has since stepped aside from his duties, but refused to resign, and faces a maximum of two years in prison.

On Tuesday, a judge heard arguments from both prosecution and defence teams during the sentencing hearing at the Newcastle Local Court but reserved the decision for until July 3.

The prosecution said there was a "breach of trust" as the 15-year-old victim "came to him for help" in 1976.

"This wasn't a split-second decision.. [Wilson] thought he'd gotten away with this for all those years," Harrison said, arguing the archbishop should be locked up to deter other religious leaders, to denounce the conduct and to recognise the harm done to the victims.

Wilson has been diagnosed with the early stages of Alzheimer's. His legal team argued that he would not be able to survive prison given his frail health condition, including suffering from diabetes, hypertension, and depression, and it "may even threaten his survival."

They also argued being jailed will put him at risk of violence from fellow inmates and that he should instead be given a good behaviour bond.

But the prosecution argued there was no evidence to suggest Wilson would be attacked in jail and "ill health cannot be a licence to commit a crime."

Outside the court on Tuesday, a survivor told reporters that it was "untenable" that Wilson argued against jail due to ill health but had not resigned from his role as archbishop.

Wilson, who was an assistant parish priest in East Maitland in the Hunter region in the 1970s, had known that paedophile priest James Fletcher was sexually abusing four boys, but dismissed their "credible allegations" because of his desire to protect the church and its reputation, the magistrate-only trial found last month.

During the trial, Wilson claimed to have no memory of a 1976 conversation he had with Peter Creigh, one of the alleged victims.

Fletcher was found guilty in December 2004 on nine counts of child sexual abuse and died in jail of a stroke a year later.