WASHINGTON — Police in Tarpon Springs, Fla., said there was "no question" that Deborah Jeane Palfrey committed suicide by hanging Thursday, but that was not enough to stop immediate speculation that the infamous "D.C. Madam" was the victim of murder.

Hustler magazine publisher and free-speech advocate Larry Flynt -- one of Palfrey's staunchest advocates -- was the strongest voice forwarding the notion that Palfrey's death was not by her own hands.

"I think the media should be very cautious in treating this as a suicide," Flynt told FOXNews.com in a telephone interview from his Beverly Hills office.

Asked if he believed Palfrey was murdered, Flynt responded: "I personally believe that's what happened, but I have no proof."

Palfrey was found guilty of federal racketeering charges on April 15 in connection to her prostitution business, Pamela Martin & Associates, which operated out of California but hired Washington, D.C.-area women for its operations.

The case drew wide attention early last year when Palfrey gave media organizations phone numbers of her clients, but not their names, in the hopes that the clients would support her claims that her business was a legitimate escort service.

Flynt was an integral part in keeping Palfrey's story public and worked with her and investigative reporter Dan Moldea to break the story that the phone number of Sen. David Vitter, R-La., was among those numbers in Palfrey's client list. Flynt targeted Vitter because he had campaigned for office on a family-values platform.

Vitter apologized in July 2007 for his name appearing on Palfrey's list, saying, "This was a very serious sin." The senator never explained his relationship to Palfrey's business. His office did not respond on Thursday to a phone message seeking comment.