Police received a report on Saturday of cash going missing after it was dispensed from an ATM machine at the Co-op store in Heckington.
A woman withdrew an amount of cash but took only her receipt. She then reported returning to the machine to find that the money had gone.
Police are hoping to track down a man captured on CCTV leaving the store in the hope that he can assist with their enquiries into the missing money.
If you know the identity of the man pictured on their website at: www.lincs.police.uk, call 101 with incident reference number 240 of September 11.