The incident happened inside the Tesco store between 11.00 and 11.10 BST on Thursday, April 13, when a woman in her 70s had her handbag stolen from her mobility walker as she was distracted looking at the shelves.
Officers investigating the incident believe the man in the image may be able to assist with their enquiries and are appealing for him, or anyone who may recognise him, to get in touch.
Anyone with information is asked to call Northamptonshire Police on 101 or alternatively call Crimestoppers anonymously on 0800 555 111 quoting incident number: 23000221788