McMahon, who starred in Fantastic Four, Nip/Tuck, and Charmed, had been privately battling cancer before his passing.

A cause of death has been revealed for Aussie actor Julian McMahon, who played Dr. Doom in two “Fantastic Four” movies and Christian Troy in the TV drama “Nip/Tuck,” among other roles. McMahon died of cancer, according to a statement from Kelly McMahon, his wife.

Actor Julian McMahon, best known for his roles in "Nip/Tuck" and "Fantastic Four," has died at age 56 after a "valiant" battle with cancer.