'Prison Break' star joins 'Heroes'

Robert Knepper has joined the cast of Heroes, says The Hollywood Reporter.

The actor - Theodore 'T-Bag' Bagwell in Prison Break - will play the new lead villain on the NBC show.

Knepper has been cast as Samuel, a charismatic but evil character who will veer into the lives of all heroes.

NBC recently announced that Heroes will return in the Fall for an uninterrupted run of 19 new episodes.