(CBS) Trouble is reportedly brewing on the set of NBC's "The Biggest Loser."
Insiders tell TMZ the remaining contestants have walked off the show and are now threatening to quit completely.
It all stems from a secret twist reportedly planned by producers. The move would introduce former contestants into the mix to compete for the $250,000 grand prize.
Sources say the remaining "Biggest Loser" contenders decided to bolt in the middle of shooting an episode because they think the twist could hurt their chances at the big prize. Now producers have shuttered production for a week to figure things out, reports TMZ.
NBC has yet to comment on the report.
The next "Biggest Loser" episode, airing Feb. 28, finds the players returning home for 18 days with a challenge to lose 5 percent of their body weight.
Tell us: What do you think about the reported season 13 plot twist?