Police are appealing for information after two men filled a car and a container with £100 worth of petrol and drove off without paying.
The theft happened on Friday January 10 at Morrisons in Caerphilly town.
Gwent Police said the men drove a white Ford Focus with false registration plates.
Anyone who recognises the men or has information should contact Gwent Police on 101 quoting the incident number 248 10/01/2014.