Weird asian or japanese film about a guy suspecting someone is an alien.

I’m trying to find out the name of a film I saw playing on a TV in a bar some time ago. I believe it was Japanese and featured a man who had kidnapped another man who I believe was a tourist or something along those lines, suspecting he was an alien. He seemed to be using various forms of torture to prove this person was an alien, intending to put him through trauma a human body couldn’t withstand. Thanks on advance for any help.