Manhunt, which debuted August 3 on UPN, sent 13 contestants on a six-day journey through Kauai while being chased by paintball gun-wielding "hunters." But in a new round of claims unearthed by investigative reporter Peter Lance, co-executive producer Bob Jaffe says he quit the show after Paramount TV executives allegedly asked him to rig two challenges, change the rules and reshoot new scenes--complete with scripts--in a Los Angeles park.

One former contestant also claims participants were told they wouldn't receive any cash prizes if they didn't play along and shoot the new scenes.

Jaffe, a 20-year reality show veteran and former creator of American Gladiators, says he quit the show in March, after battling with executive producer Chris Crowe, Paramount TV chief Kerry McCluggage and UPN chief Dean Valentine over concerns that footage he shot in Kauai didn't have enough conflict. The reshoots allegedly went on without him, he says, and new scenes were filmed not in Hawaii, but in L.A.'s Griffith Park and outside an editing suite in North Hollywood.

"They brought in palm trees to make it look like they were in the jungle," Jaffe tells E! Online. "My relationship ended in mid-March, and it had just reached a point where they wanted me to do a number of things I didn't want to do. They wanted to make it into a fictitious representation of what might have occurred."

Paramount vehemently denied the charges in a statement Wednesday, saying "UPN and Paramount have not supported and would not support persons or practices designed to manipulate the outcome of the show." One Paramount Television source contends that Jaffe was actually fired, and that the claims were simply the byproduct of a disgruntled employee.

The rigging allegations were revealed Wednesday by Lance, a journalist who had been investigating Stacey Stillman's manipulation charges against Survivor. Lance posted a lengthy expose about Manhunt on his Website, www.thestingray.net, featuring video stills he secretly took during the reshoots, copies of alleged Manhunt scripts and footage of another producer intervening in the game.

According to Lance, the allegations are all potential violations of FCC game-show laws, and could shake up reality television much like the Twenty-One scandal rocked game shows in the 1950s. "I found out where they were shooting and went over to Griffith Park," Lance says, "They were dressed in the same outfits" as the original shoot in Kauai. "It raises staggering questions."

Backing up Jaffe's and Lance's claims is Jacqueline Kelly, the first contestant booted from Manhunt who claims producers contacted her several times to shoot the new scenes. But she opted against it.

"I said I wasn't going to participate in fraud," says Kelly, a 36-year-old business consultant. "The game ended in Kauai. Anything after that is fraudulent."

Kelly says she and fellow contestants were told that they wouldn't receive any prize money until the last episode of Manhunt aired, but that "the show would never air unless we did the scenes." All 12 of the remaining contestants purportedly took part in the reshoots.

Manhunt was originally planned as a team effort between UPN and WWF honcho Vince McMahon, with three hulking stalkers aiming to take out the contestants as they vie for a $250,000 prize. McMahon, however, pulled out of the project after he became too busy with his ill-fated extreme football league, XFL, and another reality show for MTV, Tough Enough. "Short of pitching the concept, he hasn't been involved at all," says a WWF spokesman.

A source at UPN did acknowledge Wednesday that network executives were not pleased with the original footage that came back from the Kauai shoot. But the source said UPN was not involved beyond that and insisted that execs never asked for any new footage other than normal post-game interviews.

Jaffe, meanwhile, has moved on, producing a new series for the History Channel called Secret Passages, airing in January. But he called his experience on Manhunt "insanity" and is currently considering filing a complaint with the FCC.

"I've never seen anything like it before," he says, "and I hope to never see it again. I have a great concern for what the public is being sold, and the ramifications for this are really frightening."