ROME (CNN) -- Scotland's Roman Catholic archbishop, Cardinal Keith O'Brien, has resigned amid allegations that he abused four men studying to be priests in the 1980s.
It is the second potential scandal to emerge amid preparations for the resignation of Pope Benedict XVI this week and the conclave to select a successor.
In addition to O'Brien's resignation, Italian media has been abuzz in recent days with allegations that gay clergy may have made themselves vulnerable to blackmail by male prostitutes. That has set off speculation -- denied by the Vatican -- that a brewing scandal may have triggered Benedict's resignation.
O'Brien said he submitted his resignation to the pope months ago, citing his upcoming 75th birthday and his health, according to a statement released by the Scottish Catholic Media Office. Benedict accepted his resignation last week, the Vatican said Monday.
The resignation follows a Sunday report by the British newspaper The Observer that three priests and one former priest leveled allegations against O'Brien that date back 30 years.
The Observer did not recount details of the claims or identify any of O'Brien's accusers, but said one of the priests alleged "that the cardinal developed an inappropriate relationship with him."
O'Brien did not attend Mass at St. Mary's Cathedral in Edinburgh on Sunday, but the Scottish Catholic Media Office told CNN that the cardinal "contests these claims and is taking legal advice."
His accusers took their complaints to the Vatican representative in Britain and demanded O'Brien's resignation, The Observer reported. At the Vatican, Father Federico Lombardi, a spokesman for the church, told reporters that Benedict has been informed of the allegations.
The Irish-born O'Brien originally was scheduled to retire on March 17 -- St. Patrick's Day and his 75th birthday.
As late as last week, he appeared to be making plans to take part in the conclave, when the College of Cardinals gathers in Rome to pick a successor to Benedict.
But he said Monday that he would not be part of that gathering.
"I do not wish media attention in Rome to be focused on me -- but rather on Pope Benedict XVI and on his successor," O'Brien said in a statement released by the Scottish Catholic Media Office.
"I have valued the opportunity of serving the people of Scotland and overseas in various ways since becoming a priest. Looking back over my years of ministry: For any good I have been able to do, I thank God. For any failures, I apologise to all whom I have offended."
The allegations surrounding O'Brien add to the scandals already clouding Benedict's resignation, including lingering concerns over how the church has handled issues concerning sexual abuse by priests. The allegations about possible blackmail against gay priests are the latest to fuel speculation about Benedict's sudden and highly unusual resignation
Benedict announced his resignation on February 11, saying that at 85, he was too weak to continue his duties. He will become the first pope to step down since 1415.
The Vatican emphatically denied the allegations this weekend, with Secretary of State Tarcisio Bertone criticizing a rash of "often unverified, unverifiable or completely false news stories" as the cardinals prepare for their conclave.
Accepting O'Brien's resignation was among Benedict's last acts as pope.
It remains unclear when the gathering of church leaders who will elect the next pope will begin.
While Benedict issued an order to allow the election to begin sooner than the 15 days after the seat becomes vacant mandated by church rules, the date for the election will be set by the cardinals when they first gather, Monsignor Pier Luigi Celata said Monday at a Vatican press briefing.
It still must happen within 20 days of his resignation, the pope said.
After his retirement, Benedict is expected to head to the pope's summer residence in Rome before eventually settling in a monastery in Vatican City.
Church officials are still trying to work out what Benedict will be called in retirement. One suggestion is "pontifex maximus," Celata said. The term can be translated as "supreme bishop."
Vatican officials hope to have an answer next week, Lombardi said.
CNN's Chelsea J. Carter and Michael Pearson contributed to this report.
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