Official Exterminator 5: Enter The Victory (1988)

Special insurance investigator Nick Goldman and his partner Ken have been assigned to their toughest case yet: locate the missing “Star of India” diamond which was recently stolen from its owner Hector Bates in Paris. Not only does it transpire that Bates in on the heist, but the thieves plan to double cross him. Except that the stone is a fake, so the race is on to find out who actually has the original.