(CNN) -- The head of the largest Catholic archdiocese in the United States faced a grueling five-hour deposition last month, answering questions about his knowledge of abusive priests and his attempts to prevent the information from reaching police.

A spokesman for the Archdiocese of Los Angeles, California, would not answer further questions about Cardinal Roger Mahony's deposition in a civil lawsuit.

"A transcript has not been made available to the archdiocese," spokesman Tod Tamberg said. "When the transcript is made available to the public, you [CNN] may resubmit your questions."

CNN reported last year that the U.S. attorney in Los Angeles had launched a federal grand jury investigation to determine if Mahony violated the law in his response to the molestation of children by priests.

Tamberg said the archdiocese's attorneys "have been told that Cardinal Mahony is not a target of the investigation."

Sources close to the investigation said both the federal investigation and the civil lawsuit focus on one priest in particular -- Michael Baker, who was defrocked and is serving a 10-year prison term for molesting three children.

Baker, who confessed to Mahony in 1986, has twice appeared before the federal grand jury, sources tell CNN.

Mahony failed to disclose Baker's self-reported crimes to police on several occasions and instead allowed Baker to seek treatment options while moving him from parish to parish, sources close to the investigation said.

In a deposition released last year, Monsignor Richard Loomis, the former vicar of clergy for the archdiocese, said under oath that he wrote a memo in 2000 advocating that the archdiocese inform police about allegations of sɛҳuąƖ abuse against Baker. Mahony, Loomis testified, directed him not to report the allegations.

The Archdiocese of Los Angeles released information about Baker to the police in March 2002. Baker was convicted in 2007.

The archdiocese, with 288 parishes in 120 cities throughout southern California, serves more than 4 million Catholics, according to its Web site.

Mahony has dealt with accusations he covered up sex-abuse cases for years. Three years ago, the archdiocese agreed to pay $660 million to 508 people who claimed they were victims of abuse by priests.