The incident occurred at around 4.30pm on Monday February 26, when a lady withdrew £150 from the ATM outside the Co Op store in Seacroft Road.
Unfortunately, the victim of the theft walked away without picking up the money.
When she returned to the machine a few minutes later, another woman was walking away after using the machine. She was asked if she had seen the money but simply laughed.
PCSO Billy Spence said: “There is no such thing as ‘finders keepers’ and theft by finding is an offence.
“In this circumstance, it was obvious to anyone that taking the money was wrong, both legally and morally, and I would appeal to the person concerned to do the right thing and return the money”.
Anyone with information should contact PCSO Spence by calling 101, quoting incident 255 of February 29.