The same stolen number plate has been used in most of the 17 incidents, although different cars have been used.

Police are studying CCTV footage, to discover whether one man, or two of similar appearance, are responsible.

Stations in Ashton-under-Lyne, Sale, Rusholme, Eccles, Altrincham, and Stalybridge have been targeted.

The men shown on the footage are both Asian or mixed race about 5ft 11in tall, stocky, and aged between 25 and 30.

Black Volvo

The thefts have taken place at Mayenstone petrol station on Manchester Road in Ashton in March and April 2006 this year.

On two occasions, six weeks apart, they filled up with �52.51 worth of petrol in a black Volvo, with the stolen plate R218 UDD, and drove off. The plate was taken from a car in Rusholme in October last year.

In April, a black Subaru Impreza with the number plate was filled with petrol at the same station.

A week later, a black Volvo with the stolen registration number R684 BRJ was also filled with fuel, without the driver paying. Police believe it is linked to the other thefts.

The offences began in December in Stalybridge.