(CNN) Cardinal Theodore McCarrick, who led the Archdiocese of Washington and was a political force in the nation's capital, said on Wednesday that he has been removed from public ministry by the Vatican because of a decades-old allegation of sexual abuse.

The Vatican secretary of state, Cardinal Pietro Parolin, "at the direction of Pope Francis," told McCarrick that he is no longer to exercise his priestly ministry in public, said Cardinal Timothy Dolan of New York, whose archdiocese led the investigation.

McCarrick was also accused three times of sexual misconduct with adults "decades ago" while he served as a bishop in Metuchen and Newark, New Jersey, the current bishops of those cities said on Wednesday. Two of those allegations resulted in settlements, the bishops said.

As a cardinal, McCarrick is one of the highest-ranking American leaders in the Catholic Church to be removed from ministry because of sex abuse charges. Now 87, McCarrick retired at age 75, the mandatory age for Catholic bishops. He maintains his innocence.

"While I have absolutely no recollection of this reported abuse, and believe in my innocence, I am sorry for the pain the person who brought the charges has gone through, as well as for the scandal such charges cause our people," McCarrick said in a statement. He did not address the accusation or settlements in New Jersey.

McCarrick, who lives in a retirement home in Washington, could not be immediately reached for comment. A spokesperson for the Archdiocese of Washington said he is not giving interviews and referred a reporter to the statements from McCarrick and the archdiocese.

"While saddened and shocked, this archdiocese awaits the final outcome of the canonical process and in the meantime asks for prayers for all involved," the Archdiocese of Washington said in its statement . Under church law, McCarrick has the right to appeal his case to the Vatican. Because of the statute of limitations in New York, secular law does not apply.

McCarrick said he was informed several months ago that the Archdiocese of New York, where he was an ordained a priest in 1958, was investigating an allegation of abuse from a teenager "from almost fifty years ago." The cardinal said was "shocked" by the report but cooperated with the investigation.

The Archdiocese of New York, which led the investigation, said it would not release specific details about the allegation to protect the victim's privacy. But the archdiocese said a review board composed of jurists, law enforcement experts, parents, psychologists, a priest and a religious sister found the allegations against McCarrick to be "credible and substantiated."

The accusation was also turned over to law enforcement in New York, according to the archdiocese.

Patrick Noaker, the attorney for the man who made the accusation against McCarrick, said his client was molested by McCarrick on two separate occasions, once in 1971 and once the following year. Noaker said his client has asked to remain anonymous because he is still processing the news of McCarrick's removal.

Both alleged incidents, Noaker said, occurred at St. Patrick's Cathedral as his client, an altar boy, was being fitted for a cassock for Christmas Mass. At the time, McCarrick was secretary to Cardinal Terence Cooke, New York's top churchman.

"McCarrick started measuring him, then he unzipped his pants, stuck his hand in and grabbed his genitals," Noaker said. The lawyer said his client, who was about 16 at the time and a student at a Catholic high school in New York, pushed McCarrick away. "One thing he distinctly remembers is that McCarrick told him not to tell anyone about it," Noaker said.

The second alleged incident occurred the following year, again during a fitting for cassocks before the big Christmas Mass at St. Patrick's Cathedral. Noaker said his client was unsure about whether to go, but that McCarrick was not in charge of the fittings. But the future cardinal confronted his client in the bathroom, Noaker said, again molesting his client, sticking his hands down his pants.

"He brushed him away and avoided McCarrick like the plague from then on," Noaker said.

The attorney said his client is pleased that the Archdiocese of New York heard and believed his claim, which he brought to their attention in January through its Independent Reconciliation and Compensation Program.

"He knows who the powerful people are here," Noaker said. "That's one reason it took him so long to come forward. "But he feels good that people believed him."

For many years, McCarrick, who led the Archdiocese of Washington from 2001-2006, was known as a genial and effective advocate for the Catholic Church's political priorities, particularly focusing on the plight of Christians and other religious minorities in the Middle East. As the leading Catholic in Washington, he hobnobbed with presidents and other powerful figures, earning a reputation as someone who could work with both parties.

President George W. Bush stands with Cardinal Theodore McCarrick in 2005.

As a cardinal, McCarrick participated in the conclave that elected Pope Benedict XVI, who resigned in 2013.

But McCarrick said, "I will no longer exercise any public ministry." The Catholic Church has used removal from public ministry to discipline clergy who are credibly suspected of sexual abuse. It basically means that McCarrick is not allowed to perform priestly functions, like celebrating Mass, in public.

The Archdiocese of New York said "the matter is now in the hands of the Holy See," which has the final say in determining the outcome for the once-powerful cardinal.

"This could range from living a life of prayer and penance, to a dismissal from the clerical state," the Archdiocese of New York said.

McCarrick plans to appeal his case through the Catholic Church's canonical process, said Bishop James F. Checchio, of Metuchen, New Jersey, where McCarrick was a bishop from 1982-1986.

The Archdiocese of New York said that no other credible accusations of abuse have been made against McCarrick.

Two dioceses in New Jersey, however, where McCarrick was a bishop, said "there have been allegations that he engaged in sexual behavior with adults."

"This Archdiocese and the Diocese of Metuchen received three allegations of sexual misconduct with adults decades ago; two of these allegations resulted in settlements," Cardinal Joe Tobin of the Archdiocese of Newark said. Checchio said the same in his statement on Wednesday.

"As clergy in God's church, we have made a solemn promise to protect children and young people from all harm," Cardinal Daniel DiNardo, president of the US Conference of Catholic Bishops, said in a statement. "This sacred charge applies to all who minister in the church, no matter the person's high standing or long service. This morning was a painful reminder of how only through continued vigilance can we keep that promise."