Twilight star Robert Pattinson reportedly blew his top at a comedy club in Los Angeles - when a funnyman performed a routine about Heath Ledger.

An unnamed act at the Improv in Hollywood shocked the audience with his impersonation of the late Dark Knight star, which included collapsing onstage and faking convulsions, according to reports.

A witness at the event on December 16 insists Pattinson and his pals booed the comic, yelling out: "F**k you! You suck! Leave Heath Ledger alone!"

A source tells Us Weekly magazine, "Robert and his friend went nuts yelling at him... The comic didn't know who it was, but I'm sure he found out later!"

Ledger died of an accidental overdose of prescription drugs at his Manhattan home in January.