Bloodsport 4: The Dark Kumite

BloodsportThe Dark Kumite is the fourth and final film in the Bloodsport franchise. It was released directtovideo in 1999 and stars Daniel Bernhardt as police officer John Keller.

Though Daniel Bernhardt stars in all Bloodsport films except the first, his character is not Alex Cardo from Bloodsport III but it is now John Keller in this film.The prison sequences were shot at a real prison in Bulgaria and actual prisoners were extras in the scenes. Although the film was shot in Bulgaria, Bloodsportis set in the USA. This not only makes it the only Bloodsport movie set there, but the only Bloodsport movie to not be set where it was shot. ........

Source: Wikipedia