f someone said they could double your money with a secret formula, what would you do? It's one of the oldest scams in the book, and police say hucksters have been running it right here in Tampa. Watch the video of the arrest

Undercover detectives just arrested three Liberian Nationals who allegedly ran the scam out of their hotel room in Tampa. They say the men took their cash, wrapped it in tape and dipped it in a bucket of chemicals, then tried to switch it for a worthless rag also wrapped in tape.

"It's sleight of hand, and people actually fall for it," said Tampa Detective Fred Naranjo.

Detectives say the suspects' secret formula was actually Coke, ammonia, and iodine. They are asking anyone who may have been ripped off to give them a call.

According to investigators, the suspects approached people and told them they had a magic chemical. Police say they claimed it would transfer ink from money to blank white paper.

Detectives say there's are at least two variations to this scam. Sometimes they show the victims black paper, claim its painted money they smuggled through customs, then sell chemicals they claim will get the paint off.  Sometimes they offer the formula that clones money. In this version, they tell victims they have wait six hours before you open the tape, and that's how victims get duped.

Police say the suspects have been here since Saturday, and were in Orlando before that. They don't know how many victims they may have scammed.

Detectives arrested the suspects in an undercover sting. They've been charged with grand theft and scheming to defraud