The suspect entered Barclays bank holding a grey bucket at 1pm on Monday, October 24, when the branch was packed with customers waiting to make transactions.
Police stormed into the bank in Lumley Road, Skegness, and arrested him leaving money scattered over the floor.
A customer filmed as three officers pinned the man down while another scrambled on her hands and knees as she picked up the money.
An eyewitness said: “The man was being served at the counter and he was carrying a little bucket.
Customers presumed some kind of bank robbery had been foiled, but Chief Insp Jim Tyner said: “There was no robbery. Officers were making an arrest for an unrelated matter.”