THE Pope's envoy to the UK has praised the work of disgraced Cardinal Keith O'Brien, saying he should not be judged on the allegations of improper sexual conduct against him.

Papal Nuncio Antonio Mennini said although the cardinal made mistakes, he had done a "lot of good for the church" as Archbishop of St Andrews and Edinburgh.

Archbishop Mennini said finding a replacement for the cardinal was a priority for the Catholic Church in Scotland, which needs to appoint bishops in four of its eight dioceses.

Cardinal O'Brien, 75, resigned in February after three serving priests and one former priest alleged improper conduct in the 1980s.

The cardinal accepted his sexual conduct had "fallen below the standards expected of me as a priest, archbishop and cardinal".

He has since left Scotland for "spiritual renewal, prayer and penance".

The Papal Nuncio said that "in some aspects, notwithstanding his mistake" the cardinal had done "a lot of good for the Church".

He added: "We cannot judge the cardinal only for these very serious events, because in every person there is black and white, we have positive and negative."

He anticipated that a decision over who would replace Cardinal O'Brien as Archbishop of St Andrews and Edinburgh would be made next month, saying it was a priority for the church.

The departure of the Bishop of Motherwell, Joe Devine, confirmed on Tuesday, means that of the eight dioceses in Scotland only three have full-time bishops in post who are not waiting to leave – Glasgow, Oban and Aberdeen

The Papal Nuncio said bishops will also be appointed to fill vacancies in Paisley and Dunkeld by the end of the summer.

Cardinal O'Brien was Britain's most senior Roman Catholic cleric until he stood down as the Archbishop of St Andrews and Edinburgh. He had to abandon plans to retire to the parish house in Dunbar, East Lothian, after concerns were raised about his public profile.

It was confirmed on Wednesday that Bishop Devine's role will be handed over to an administrator while the the diocese looks for a permanent successor.

Last month his office was rocked by allegations that questioned how Bishop Devine handled abuse cases.

Alan Draper, a former child protection consultant for the Scottish Catholic church, claimed he had stopped working for Bishop Devine because his advice was consistently ignored.