Pope Francis has appointed Gregory O’Kelly, the bishop of Port Pirie, the special administrator of Adelaide following the conviction of Archbishop Philip Wilson for covering up child sex crimes during the 1970s.

Greg O’Kelly, who has been named the special administrator of Adelaide. Photograph: Australian Catholic Bishops Conference

O’Kelly, who will remain the bishop of Port Pirie, north of Adelaide, assumes administrative and executive authority in the archdiocese until any future decision of the Pope, the Australian Catholic Bishops Conference said in a statement.

Wilson was found guilty at Newcastle local court on 22 May of failing to report to police the repeated abuse of two altar boys by paedophile priest James Fletcher in the New South Wales Hunter region.

He is the most senior Catholic official in the world to be charged with concealing child sexual abuse.

He stood aside following the court’s decision but has refused to resign.

Wilson, who faces a maximum two years in jail, is expected to be sentenced this month.