Police have released this CCTV image as they re-appeal for witnesses following an incident at Marks and Spencer in London Road, Wellingborough.
Some time between 2pm and 2.30pm on Sunday, January 22, a man paid for a small number of items with a £50 note, but during the transaction, he deliberately confused the cashier by asking to change various notes that he had for money inside the till.
A police spokesman said: “In all, he managed to obtain about £300 in notes before making a swift exit from the store.
“He was chased and shouted out but made it to an awaiting small blue car where he escaped with an accomplice.”
He is described as white, in his mid to late 20s with short brown hair and glasses.
He wore a black parka-style coat and dark jeans.
Anyone with information can contact Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.