Cardinal Keith O'Brien will face a Vatican inquiry after admitting that his sexual conduct "had fallen beneath the standards" expected of him during his almost 50-year career.
The cardinal shocked the Roman Catholic community on Sunday when he indicated that he would not contest claims against him and intended to retire permanently from the public life of the church.
The admission came a week after three priests and a former priest accused Britain's most senior Catholic cleric of inappropriate behaviour dating back to the 1980s.
The cardinal, who stepped down from his post as Archbishop of St Andrews and Edinburgh in the wake of the scandal, has asked for forgiveness from those he had offended.
In a sweeping apology issued on Sunday, he said of the claims: "Initially, their anonymous and non-specific nature led me to contest them. However, I wish to take this opportunity to admit that there have been times that my sexual conduct has fallen below the standards expected of me as a priest, archbishop and cardinal."
The complaints have been reported to the Vatican, and a Scottish Catholic Media Office spokesman said: "We expect that they will be investigated and a conclusion drawn." The inquiry is not likely to begin until after a new pope is chosen. It is understood the cardinal, who will not attend the conclave, is currently out of the country.
The cardinal, who was born in Ballycastle, Co Antrim, had been the Archbishop of St Andrews and Edinburgh since 1985. Ordained as a priest in 1965, he was proclaimed a cardinal by Pope John Paul II in October 2003. He was Britain's most senior Catholic cleric.
One of Scotland's most outspoken opponents of moves to legalise same-sex marriage, he was last year named "Bigot of the Year" by gay rights group Stonewall.
The claims against him were reported in the Observer newspaper last Sunday and the following day it was announced that the cardinal would quit his post with immediate effect.
His resignation was in fact accepted by the pope on February 18. The cardinal had been due to retire later this month when he turned 75 and the Scottish Catholic Media Office said his resignation had not been accelerated because of the allegations.