The “Crypto King of Kentucky” suspected of torturing a man for weeks inside a swanky multimillion-dollar New York City townhouse spent big at a super exclusive erotic night club … TMZ has learned.

Sources with direct knowledge tell us John Woeltz and his alleged accomplice William Duplessie started going to a club called The Box back in February, and there were nights where they would drop between $80,000 and $100,000 … and we have photos and videos of them in the club.

The Box bills itself as a unique and exclusive club featuring nightly shows combining music, theater, burlesque and erotica … and there’s supposedly a sexy peep show.

We’re told William, a Swiss businessman, was always shirtless inside The Box … because he wanted to act like the man and thought he was in the mafia.

Our sources also say William would explain his shirtless preference by claiming people wouldn’t take him seriously if he had a shirt on.

William’s drink of choice at The Box, we’re told, was Don Julio 1942 tequila and Champagne … with William drinking his booze straight from the bottle.

Eventually, John and William moved into The Mercer hotel before transferring to a fancy townhouse in SoHo, where we’re told they would bring lots of girls back from The Box for afterparties.

Our sources say John and William even hired promoters to bring the girls back to their pad … and the women were mostly models from IMG and Wilhelmina.

Our sources say William also loved smoking American Spirit cigarettes. We’re told John and William were partying like every day was their last and lived their lives on the edge … but it was all a facade.

John, we’re told, didn’t want to live in New York … but Will convinced him to live there … and our sources described William as the male version of infamous con artist and fraudster Anna Delvey.

Cops say Carturan ultimately escaped the townhouse where he was allegedly being tortured for the password to his Bitcoin fortune … and he told police everything.

John was arrested Friday in nothing but a bathrobe and he’s charged with multiple felonies … including assault, kidnapping, unlawful imprisonment and weapons possession.