Tokyo metropolitan police said the four men were arrested July 3-5 on suspicion of using cocaine in Tokyo or nearby areas in violation of drug laws.
NHK public television reported the four men entered Japan between February and May and were living in Tokyo.
They reportedly were drinking at a bar in Tokyo’s entertainment district of Roppongi, where one of them allegedly intruded into an apartment complex, leading to police questioning and arrests. The four men denied the police allegations, but they tested positive for cocaine, NHK said.
The incident took place before a state of emergency took effect Monday in Tokyo that mainly attempts to curb public alcohol consumption during the Olympics. It asks bars and other such venues to close or not sell alcohol for six weeks.
The Olympics begin July 23.