TAFT, Calif. – Five years ago, Aaron Tonken was riding high, hobnobbing with Hollywood celebrities and helping to raise millions for the Senate bid of first lady Hillary Clinton.

Tonken’s life these days is neither flashy nor frenetic. Since September, he’s been in a federal prison north of Los Angeles serving a 63-month sentence for mail and wire fraud.

The abrupt end to Tonken’s career as an organizer of charity fund-raisers delivered a financial blow to the foundations he worked with and a public relations headache for the entertainers he accused of profiting from ostensibly charitable events.

Now, however, there are new signs that Tonken’s demise could become a thorny political problem for Senator Clinton as she prepares to run for reelection and considers a bid for the presidency in 2008.

Last month, a federal court un sealed an indictment charging the national finance director for Mrs. Clinton’s 2000 campaign, David Rosen, with four counts of causing false reports to be filed with the Federal Election Commission. All of those charges stem from a star-studded August 12, 2000, gala fund-raiser that Tonken organized and billed as a “Hollywood Salute” to President Clinton.

In his first in-person interview since he went to prison, Tonken, 39, spoke with The New York Sun last week about the FBI’s investigation into his claims that Mrs. Clinton’s campaign hid millions of dollars in in-kind donations. During the 90-minute exchange, he also alleged that federal agents targeted the then-first lady in 2000 and sought to establish her role in the alleged fraud.

While Mr. Rosen, the finance chief, pleaded not guilty to the charges, Tonken said the allegations of gross misreporting of fund-raising expenses by Mrs. Clinton’s campaign are true, and knowledge of the practice was not limited to Mr. Rosen.

“Everyone around her knew there was a crime in what was going on,” Tonken said. He said Mr. Rosen repeatedly instructed him to lose or get rid of invoices for expenses related to the August 2000 fund-raiser, including $9,280 for the finance chief’s own three-week stay at a Beverly Hills hotel. A copy of the hotel bill appears in Tonken’s recently published book, “King of Cons.”

Mr. Rosen’s attorney, Paul Mark Sandler, said the indictment of his client was unjustified. “Mr. Rosen is innocent and will not debate or try the case in the media but is eager for a speedy trial where the facts will come out,” the lawyer said. He disputed Tonken’s claims, but declined to make Mr. Rosen available for an interview.

“It’s very tempting to respond specifically…but I believe it’s most responsible to resist those temptations and present the case in court,” Mr. Sandler said.

In the indictment, the government asserts that expenses for the gala exceeded $1.2 million and that about half of that amount was omitted from reports filed with federal election officials. However, Tonken said the true cost of the fund-raiser, which featured performances by Cher, Paul Anka, and others, was much higher.

“The event cost millions…as much as $2.4 million,” Tonken said.

In other court filings, federal investigators have indicated they believe Mrs. Clinton’s campaign deliberately understated in-kind donations to maximize its take of so-called hard money. Under the law at the time, “hard money” could be spent directly on the Senate campaign, while “soft money” gifts were restricted primarily to the Democratic Party’s get-out-the-vote efforts in New York.

Tonken said he organized five other fund-raisers for the first lady, including a private lunch at Spago’s restaurant in Los Angeles, a tea at the home of a Beverly Hills philanthropist, another tea with Cher, and a dinner in Chicago where Olivia Newton-John sang. In each case, Tonken said, he incurred expenses that Mrs. Clinton’s staff told him not to report.

At one point during the fall of 2000, he bragged to Mrs. Clinton about all the campaign-related costs he had assumed.

“I did tell Hillary. I got her alone in the van one time and I told her,” Tonken said. “I’m telling her, ‘I did this for you. I did this for you.’ I was insecure and wanted to build myself up. She, I’m sure, doesn’t want to calculate it …but big numbers were given to her.”

Tonken said he doubts Mrs. Clinton realized that the lavish spending could lead to false reports being filed with the FEC. “It doesn’t register, oh, this, you know, is going to be a crime,” he said.

A spokesman for Mrs. Clinton, Philippe Reines, referred all questions about the matter to her private attorney, David Kendall.

“Mr. Rosen worked hard for the campaign and we trust that when all the facts are in, he will be cleared,” Mr. Kendall said. “We have cooperated fully with the investigation.”

Last fall, prior to the unsealing of Mr. Rosen’s indictment, Mr. Kendall told the Associated Press the campaign “properly reported all contributions.” He declined to repeat that statement yesterday.

As a convicted felon and admitted con man, Tonken’s credibility is obviously suspect. However, the indictment of Mr. Rosen shows that the Justice Department believes at least part of Tonken’s tale.

Precisely when and why federal authorities began investigating the fundraising practices of Mrs. Clinton’s Senate campaign remains a mystery. However, the first inquiries appeared to follow a gossip item published in the Washington Post three days after the Hollywood gala. The newspaper reported that one of the organizers of the event, Peter Paul, was a thrice-convicted felon. Paul and Mrs. Clinton’s campaign initially denied that he had made any financial contribution to her candidacy. However, an aide to Mrs. Clinton said a few days later that the campaign was returning a $2,000 check from Paul.

The FBI came calling soon thereafter, Tonken said. “I started cooperating a month after August 2000. They came to me,” he said. He said he told FBI agents that Paul and his company, Stan Lee Media, bankrolled the Hollywood fundraiser and that Mr. Rosen had worked out of the company’s offices.

Tonken said the agents took interest in the campaign’s handling of in-kind gifts. He said he went on to become a full-fledged informant. “I wore wires. I wore live wires, recorded wires. The agents would be across the street,” he said.

According to Tonken, FBI agents eventually set up recording equipment in his home and left instructions to record any phone calls with Mrs. Clinton, Mr. Rosen, or a longtime traveling aide to the former first lady, Kelly Craighead.

Tonken has numerous phone machine messages from Mrs. Clinton thanking him for his work. However, by the time the FBI’s equipment was in place, Mrs. Clinton and the others stopped taking his calls. “I couldn’t get any of the three of them on the phone,” he said.

Tonken said he nevertheless kept Mr. Rosen and Ms. Craighead apprised of the investigation. He said he saw Mr. Rosen soon after the probe started and asked him what he was going to tell the FBI about the extra expenses. According to Tonken, Mr. Rosen said, “I’m going to say, ‘I didn’t know.’ “

Tonken said he regularly informed Ms. Craighead via e-mail about the unrecorded expenses and about the FBI’s inquiries. He said she responded that she was passing the information on to two close aides to Mrs. Clinton: her campaign chief of staff, Patricia Solis Doyle, and the White House social secretary, Capricia Marshall.

Tonken said he assumed the women kept the details from Mrs. Clinton. “They would e-mail back and forth and not tell me if they told her,” he said.

In an interview, Ms. Solis Doyle denied Tonken’s claim that she knew about the unrecorded expenses. “That’s not true,” she said, declining to discuss the matter further.

Ms. Craighead did not return calls seeking comment for this story. Ms. Marshall said she did not wish to comment.

A Justice Department spokesman said the investigation has concluded and no more indictments are expected.

Tonken eventually had a falling-out with the federal authorities. His attorney said prosecutors deemed him “not credible.” However, Tonken said that last November, the top prosecutor on the Rosen case, Noel Hillman, again sought to gain Tonken’s cooperation. He said he refused.

A high school dropout from Michigan who stayed for a time in a Los Angeles homeless shelter, Tonken rose to the top of Hollywood’s charity scene through flattery and the unsavory technique of using cash and lavish gifts to entice celebrities to appear at galas. That practice eventually proved to be his undoing, because his costs often exceeded the money raised through ticket sales, auctions, and the like. Tonken began wildly shifting funds and borrowing to satisfy angry charities. Some never got paid, and soon investigators from the California attorney general’s office were on his tail.

Tonken said he found that his brand of largesse also opened doors in Washington. The first political fund-raiser he attended was in 1998 ,at the Manhattan apartment of Denise Rich, the songwriter and philanthropist who helped persuade Mr. Clinton to pardon her husband, Marc.

Tonken said his ability to deliver donations and performances from Hollywood stars made him fast friends with Democratic Party officials. The fundraisers for Mrs. Clinton also made him popular at the White House.

According to Tonken, in the last five months of 2000, he received 14 invitations to White House events, including the state dinner for the Prime Minister of India.

Tonken claimed that during his visits to the executive mansion that fall he gave gold Rolex watches to several aides to Mr. Clinton. In the interview last week, Tonken alleged that the director of political affairs, Minyon Moore, and the Midwest political director, Orson Porter, were among those who received watches. In his book, Tonken wrote that Mr. Porter never took any gifts. Ms. Moore and Mr. Porter did not return calls seeking comment on Tonken’s assertions.

Tonken said he also gave a Hawaiian vacation and a gold Baume & Mercier watch worth $10,000 to Ms. Craighead. He said she kept the watch for a year, returning it only after an FBI inquiry.

Only one member of the Clintons’ staff spontaneously rejected a gift, Tonken said. He said Mr. Clinton’s personal aide, Douglas Band, immediately returned $5,000 worth of luggage placed in his hotel room during one of the president’s trips.

Tonken said he harbors no ill will toward any of the players in the saga, except for federal prosecutors who he said gave him no credit for his information about the Clintons and Hollywood. He called Mr. Rosen and Ms. Craighead “decent.” He also said prison has been a “blessing” for him.

As a convicted felon, Tonken won’t be voting anytime soon. However, he said will support Mrs. Clinton if she makes a bid for the White House in 2008. “I think she would make a fantastic president,” he said.