(Adds Vatican no comment, historical details, Wilson appeal; paragraphs 7-9)
By Colin Packham
SYDNEY, July 19 (Reuters) - Prime Minister Malcolm Turnbull said on Thursday that Pope Francis must sack an Australian archbishop convicted of concealing child sex abuse.
In May, Archbishop Philip Wilson, 67, became the most senior Catholic cleric to be convicted of not disclosing to police abuse by another priest.
Wilson, who was sentenced to a year's detention this month, has stepped aside as archbishop of Adelaide in South Australia state, but has not resigned, insisting he will do so only if he is unsuccessful in an appeal.
Turnbull, who has previously called on Wilson to resign, escalated his criticism of the archbishop remaining in office.
"He should have resigned and the time has come for the Pope to sack him," Turnbull told reporters in Sydney. "I think the time has come now for the ultimate authority in the Church to take action and sack him."
The archdiocese of Adelaide was not immediately available for comment.
The usual procedure is for a bishop to offer his resignation to the pope, but Wilson has said he will appeal the sentence and not resign unless he loses.
The Vatican had no comment on Turnbull's remark, one of the sharpest interventions by a politician concerning the Catholic Church since former Irish Prime Minister Enda Kenny accused the Holy See of obstructing investigations into sexual abuse by priests in 2011.
That prompted the Vatican to recall its ambassador in Ireland for consultations.
Lawyers for Wilson, who maintained his innocence throughout his trial, had argued that he did not know priest James Fletcher had committed child sex abuse throughout the 1970s. The court was told that two victims, one an altar boy, told Wilson of the abuse in 1976.
Fletcher was found guilty in 2004 of nine counts of child sexual abuse and died in jail in 2006 after a stroke.
Wilson remains on bail while he is assessed by prison authorities for home detention, instead of jail.
Diagnosed this year with early onset Alzheimer's disease, Wilson is to face court again on August 11, for a ruling on whether he will be imprisoned or allowed to serve his sentence in home detention.
Accusations of sexual abuse cover-ups have continued to rock the Catholic Church years after perpetrators of sexual abuse started regularly appearing before the courts.
In May, all 34 bishops in Chile offered to resign over allegations of a cover-up of sexual abuse.