A Pentecostal minister who told the FBI of an affair between his then-18-year-old daughter and Rep. Gary A. Condit informed investigators this week that he had fabricated the story, a law enforcement source said today.

The account provided by Otis Thomas, published by The Washington Post on July 12, was widely circulated in the media and increased the pressure on the California Democrat. A note signed "Jennifer Thomas" that appeared on the front door of the Thomas residence that same day dismissed the minister's story and said: "I never met the congressman who's involved in all of this."

It is unclear whether the minister disavowed all or parts of his account, which he provided to the FBI in May. But one law enforcement official said that the FBI had been trying to interview Thomas's daughter and that Thomas "backed off" the story in the last few days.

Condit's representatives, who called The Post's July 12 story "reckless and deplorable," did not return telephone calls seeking comment today.

In another development, two law enforcement sources confirmed that police retrieved a watch case from a trash can in an Alexandria park, apparently deposited there by Condit in the hours before his Adams Morgan apartment was searched by police. The report, first broadcast Thursday night by WUSA-Channel 9 in Washington, said investigators had traced the box to a California woman.

One law enforcement source said Condit apparently was trying to hide an affair with the woman, who has not been identified. Another law enforcement source said that the watch was from someone else and that it did not appear to be related to the investigation into the disappearance of intern Chandra Levy, 24.

Thomas, 54, was approached by the FBI in May, after Levy's parents told investigators that Thomas had told them in mid-April that his daughter had had a relationship with Condit. In six lengthy interviews, Thomas, a part-time gardener at the Levys' California home, told The Post that his daughter had broken off the relationship with Condit and that Condit had warned her at the time not to tell anyone of the affair.

A spokesman for the Levys said today that the family did not understand why Thomas would fabricate a story in mid-April, weeks before their daughter disappeared.

"The conversation between Mr. Thomas and Mrs. Levy took place just as it was reported, and Mrs. Levy had no reason to doubt whether he was telling the truth," family spokesman Mike Frisby said today. "When I spoke to her this morning, she even recalled that Mr. Thomas had tears in his eyes when he told the story. . . . I don't believe the Levys, who are only interested in finding their daughter, would pressure anybody to say something that wasn't true."

Thomas said he told the FBI of the relationship during an interview conducted here by Special Agent Todd M. Irinaga. Four law enforcement sources confirmed that the minister had been interviewed and that authorities were interested in talking to the daughter. For several weeks, Thomas said he tried to persuade his daughter to talk to the FBI, but he said she refused and even traveled out of the state to avoid coming forward.

Susan Levy, Chandra Levy's mother, confirmed Thomas's account in interviews in May and June. She said she called her daughter in Washington, told her what Thomas had relayed and urged her to break off her relationship with Condit. About two weeks before she vanished, Chandra Levy called her mother and told her Condit had "explained it all," Susan Levy said.

She said that after her daughter disappeared, she asked Thomas again about his daughter's relationship with the congressman, specifically requesting details about why and how it ended. After that, the minister was under intense pressure to come forward. At one point, his name was made available to other media, prompting a stakeout at his home.

In a brief interview with The Post before the story appeared, Thomas's daughter was asked whether her father's account to the FBI was true. She replied that she did not want her photograph in the newspaper and then said, "I don't want to talk about that."

Thomas, who left the Modesto area after the story was published but has since returned, stood by his initial account in an interview earlier this week.

"Why would she lie about that? Why would I lie about that? I have nothing to profit from this," Thomas said. Of his daughter, he said: "She's so angry with me, she doesn't even want to talk to me. She's scared. She's a very quiet and shy person to begin with, so she doesn't want all this attention."

Details of Thomas's latest interview with the FBI were scant today. WUSA and other media, citing unnamed sources, said Thomas told authorities that he fabricated his account but did not provide specifics. Chris Murray, a spokesman for the FBI's Washington field office, and Channing Phillips, a spokesman for the U.S. attorney's office in Washington, declined to discuss Thomas.

For weeks, the Levy family has been pressuring Condit, urging him to be more forthcoming. Chandra Levy had told relatives of an affair with the congressman, but Condit, through his aides, had denied any romantic involvement. He acknowledged an affair during a third interview with police, according to two sources familiar with the meeting.

Meanwhile, law enforcement sources said a male friend of Chandra Levy's who had been interviewed several times took and passed a polygraph test on Thursday. The person said in an interview that he had also provided police with credit card and airline records showing he was out of town near the end of April. Levy was last seen April 30.

D.C. police also revealed 30 Web sites visited by Levy on May 1, when she spent about 3 1/2 hours on her computer. In addition to visiting the sites of several media outlets, Levy called up the site of the House Agriculture Committee, of which Condit is a member, and several travel sites.

Staff writer Susan Schmidt in Washington contributed to this report.