HOUSTON -

There's controversy brewing on NBC's hit show "Biggest Loser."

Trainer Jillian Michaels has been accused of breaking the rules; as a result a famous constant is coming back to the show.

Michaels is known for being tough, now she's accused of breaking the show's rules by giving her contestants caffeine supplements. As a result, former 'American Idol' Winner Ruben Studdard is coming back to the show, after he was eliminated last week.

If the other trainers were hoping for an apology from Michaels, they didn't get. On the show she said she stands by her opinion that a caffeine supplement is healthier than unlimited amounts of coffee.

Michaels did say she regrets that her team is the one suffering the results of her professional opinion.

She gave the contestants the supplement without medical approval which is against the rules of the competition.

As it turns out, the supplement did not appear to give Michael's team an edge at the weigh-in. Even without a penalty figured in, the team failed to lose enough weight. That led to one of their teammate's elimination.