A New Orleans political consultant who is Senator Kennedy's brother-in-law, Raymond Reggie, has been operating in Democratic circles for the last three years as an undercover informant for the FBI, sources close to the matter said yesterday.

At a federal court hearing yesterday morning, Reggie, 43, who organized fund-raisers for President and Mrs. Clinton, pleaded guilty to two felony charges, bank fraud and conspiracy. Prosecutors described check-kiting and loan fraud schemes he operated involving three Louisiana banks, but they did not publicly detail his cooperation with the government.

The New York Sun reported yesterday that an unnamed witness with ties to a prominent political figure has been involved in recent federal investigations of campaign fund-raising violations, including a probe into alleged financial misreporting in Mrs. Clinton's bid for the Senate in 2000. The informant, described in court papers only as a "confidential witness," was part of an FBI plan to secretly audiotape conversations with political operatives, including a well-known person who prosecutors said was seeking to funnel donations from foreigners to federal campaigns.

Several people with knowledge of the case identified Reggie as the informant described in the Sun article.

In a brief interview, the first assistant U.S. Attorney in New Orleans, Jan Mann, said of the Sun story, "I wasn't sure if anybody made any of these connections yet or not." She declined to describe the investigations in which Reggie helped the government. "We're not handling anything outside of the case on Ray Reggie, so it certainly wouldn't be in my realm to talk about anything else," she said.

Reggie's lawyer, Michael Ellis, declined to comment for this article.

The disclosure that Reggie was surreptitiously recording conversations for the FBI may have caused some heartburn yesterday for Democrats who have had contact with him since 2002.

Reggie was a regular presence at Mr. Clinton's side when he visited New Orleans during his presidency and thereafter. Just last September, Mr. Clinton had lunch in that city with Reggie, as the former president swung through town to sign his autobiography and attend a $10,000-a-head Democratic Party fund-raiser, the Times-Picayune newspaper reported. A former congresswoman and ambassador to the Vatican, Lindy Boggs, joined Reggie and Mr. Clinton at the lunch, as did two federal judges whom Mr. Clinton appointed.

When Mrs. Clinton traveled to New Orleans in May 2000 to raise $100,000 for her Senate campaign, Reggie was on the host committee.

An attorney for the Clintons, David Kendall, had no immediate response yesterday to questions about Reggie's role in Mrs. Clinton's Senate campaign or about the possibility that Reggie might have taped one or both of the Clintons.

Reggie is expected to be a witness in a federal criminal case involving a finance official on Mrs. Clinton's campaign staff, David Rosen. In a trial scheduled to start at Los Angeles on May 3, Mr. Rosen, 40, faces charges that he caused false donation and expenditure reports to be filed with the Federal Election Commission in connection with a fund-raising gala at Hollywood in August 2000.

Court documents indicate that in September 2002, a confidential witness, identified by other sources as Reggie, taped an unwitting Mr. Rosen in a conversation discussing his role in the 2000 gala. In an affidavit submitted to a federal magistrate, an FBI agent asserted that the informant "was involved in the planning of the Clinton Gala."

In June 2000, Reggie and his wife, Mary Michelle, were guests at a state dinner. They also stayed overnight at the White House as guests of the Clintons.

Mr. Rosen's defense attorney, Paul Sandler of Baltimore, refused to comment yesterday on the disclosure of Reggie's role as an informant or on what impact his secret recording might have on Mr. Rosen's case. "I have nothing to say. I'm getting ready for trial in 10 days," Mr. Sandler said.

A former Internet executive who helped organize the August 12, 2000, Hollywood fund-raiser, Peter Paul, said in an interview last night that he was certain Reggie was not a key player in the gala. "If he had a role, it was a very, very small role," Paul said.

However, campaign finance records provide some indication that Reggie might have at least attended the fundraiser for Mrs. Clinton at a radio's executive's mansion in the Brentwood hills of Los Angeles.

On August 28, 2000, the committee that officially sponsored the event, New York Senate 2000, recorded a donation from Reggie of $1,330.

Reggie took out a full-page ad in a "tribute book" distributed to guests at the gala. "You have demonstrated as the president and first lady of the United States that you were willing to 'pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and the success of liberty,'" the ad read. It was signed, "With gratitude, Ray Reggie."

On separate occasions, Reggie gave another $6,000 to committees connected with Mrs. Clinton's campaign. Overall, Reggie gave about $29,000 to Democratic candidates over the past six years, Federal Election Commission filings show. Reggie also served on the national finance committee for Vice President Gore's presidential bid in 2000, according to a New Orleans publication, CityBusiness.

Reggie's sister, Victoria, is married to Senator Kennedy of Massachusetts. A spokeswoman for Mr. Kennedy did not return several phone calls yesterday seeking comment for this story. Reggie is also the son of a prominent Louisiana judge, Edmund Reggie, who was a close friend of President Kennedy.

The younger Reggie is close to and has done consulting work for the former mayor of New Orleans, Marc Morial. Press reports in Louisiana have suggested that prosecutors' interest in Reggie may have stemmed from a desire to get information from inside Mr. Morial's inner circle. Mr. Morial has not been charged with any crime.

The bank-fraud charges against the Reggie date to 2001 and earlier. Court records indicate his plea deal with the government was reached in 2002. However, the charges were not filed publicly until February of this year.

Reggie, who ran an advertising buying and consulting firm known as Media Direct, has admitted to using a forged contract with the Census Department to obtain a $6 million line of credit from a Louisiana bank. At the hearing yesterday, he acknowledged using that line of credit to cover a check-kiting scheme at two other banks. One bank lost $3.5 million, court papers said. His sentencing was set for October 23. The maximum penalty on the two charges is 35 years in prison and a fine of up to $1.25 million.

Reggie also faces a separate, unrelated state trial in Louisiana next month for allegedly impersonating a police officer. The felony charge stems from a 2002 incident in which Reggie allegedly used a blue light to stop another vehicle.

"He pulls over a car full of young girls, tells them he's a cop; and wants one of them to get out; tried to get them to follow him somewhere," the prosecutor handling the case, Kim McElwee, said in an interview.

Ms. McElwee complained that she has had great difficulty obtaining routine evidence for the case. "I've never had a case quite like this," she said. "People say they have a document. I call back. Not only is the document gone, they're gone. It's bizarre."

Reggie, who has maintained his innocence, has waived his right to a jury trial. Ms. McElwee said the judge will probably acquit Reggie. "I'm getting entertainment out of this. I'm certainly not going to get a conviction," she said.