Scottish Cardinal Keith O'Brien, who stepped down as archbishop last week amid accusations of sexual impropriety, on Sunday apologized for his past sexual conduct.

O'Brien issued a statement saying he had contested early allegations made against him because of their "anonymous and non-specific nature." He offered no specifics Sunday but did apologize for his behavior.

"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," his statement said. "To those I have offended, I apologize and ask forgiveness. To the Catholic Church and people of Scotland, I also apologize.

"I will now spend the rest of my life in retirement. I will play no further part in the public life of the Catholic Church in Scotland."

But even with Sunday's admission of violating church teachings, O'Brien remains in the College of Cardinals.

Last week, when Benedict XVI was still on the throne of St. Peter, he accepted O'Brien's request to resign as Archbishop of St. Andrews and Edinburgh, which had been offered in 2012. And O'Brien said then that although he's still under age 80 and eligible to vote for the next pope, he would not come to Rome for the upcoming conclave.

Now, Benedict has retired to the papal retreat and there's no pope -- no one with the authority to remove O'Brien as a prince of the church, church historian Matthew Bunson says.

O'Brien had been the leader of the Roman Catholic Church in Scotland and the United Kingdom's most senior Roman Catholic before stepping down. That came after media reports that several priests had accused him of inappropriate sexual behavior when he worked at a seminary in the 1980s.

The reporter who broke the story says the Vatican has known all along who accused O'Brien. Catherine Deveney of The Observer wrote Saturday, "The three priests, and one former priest, who have made complaints are not anonymous. They have given sworn, signed statements to the papal (ambassador) nuncio."

O'Brien was never the poster boy for the Vatican's positions on sexual behavior.

In 2003, as a condition of being made a cardinal, O'Brien was forced to issue a public pledge to defend church teaching on homosexuality, celibacy and contraception. He was pressured to make the pledge after he had called for a "full and open discussion" on such matters.

At the time, O'Brien said he had been misunderstood and wanted to clarify his position. But statements made last week, before the scandal over his behavior broke, suggested he never really changed his mind. In an interview with the BBC, O'Brien said celibacy should be reconsidered because it's not based on doctrine but rather church tradition and "is not of divine origin."

When he stepped down last week, O'Brien also said he would not take part in the conclave to elect a successor to Pope Benedict XVI because he did not "wish for media attention in Rome to be focused on me."

O'Brien's absence will not turn off the media attention to the church's tensions on sexuality. Cardinals gathering in Rome for advisory meetings, beginning Monday, still must deal with two troubling issues. Italian media have published anonymous rumors of gay sexuality involving priests and members of the church bureaucracy, the curia, in Rome.

And advocates for victims of sexual abuse by clergy are demanding that some cardinals, in particular Cardinal Roger Mahony, retired archbishop of Los Angeles, refrain from voting because they failed to protect children and teens from predators.

Terence McKiernan, president of BishopAccountability.org, has said, "Cardinals who are tainted by the crisis cannot choose the person who will solve it...If they are involved in the deliberations and the votes, they will taint the outcome, damaging the legitimacy of whoever is ultimately chosen."

Contributing: John Bacon in McLean, Va.; Associated Press