''It was a pretty miserable thing to do,'' Senior Constable Geoff Wyllie, of Dunedin, said.
The disabled man was waiting in the foyer of Pak'n Save, South Dunedin, with a bag of groceries hanging from his walking frame, on Monday about noon.
The offender had earlier been spotted loitering in the foyer, and ''just walked over and grabbed the bag and shot out the door like a rocket''.
''He took to his scrapers and took off across the car park.''
Snr Const Wyllie said it was despicable act from a ''ratbag'' offender.
''What we see is what we have got, just a miserable crime, picking on someone like that.''
The victim, who is aged in his 50s and had suffered a head injury when he was younger, was shaken by the incident.
Pak'n Save reimbursed the man for his groceries, which were valued at about $30.
Anyone who may be able to identify the offender is urged to contact police on 471-4800 or anonymously via Crimestoppers on 0800-555-111.
