Frank Dux

Frank William Dux is a Canadian-American martial artist and fight choreographer. According to Dux, a ninjutsu expert named Senzo Tanaka trained him as a ninja when he was a teenager. He established his own school of ninjutsu called Dux Ryu Ninjutsu, and has said he won a secret martial arts tournament called the Kumite in 1975. His alleged victory served as the inspiration for the 1988 film Bloodsport starring Jean-Claude Van Damme, but the existence of both Senzo Tanaka and the Kumite he described have been disputed.