Global giant Shell took a battering this week, when a Sutton man blamed the company for more than £2,000 in damages after an alleged fuel contamination incident.

Michael Farrell, who uses his van to deliver precious NHS blood supplies to hospitals and medical centres across the UK each week, said he was appalled by his recent visit to the Shell St George's service station in Weybridge.

He said he filled his van with diesel, settled up - and then broke down 230 miles down the road.

He said: "I started driving and then all of a sudden my van just stopped, there was no power whatsoever.

"When I got it back to the mechanics in Morden, they told me I needed a new diesel filter because my tank had been contaminated with unleaded fuel.

"That cost nearly £600 to do and then I lost six days' deliveries with the van off the road, so I lost £1,500."

He said he had two receipts, which proved he was right - one from the service station, which documented his diesel fuel purchase and another from the mechanic - stating unleaded fuel was detected in the tank.

Robins and Day Morden service manager, Trevor Guy, who dealt with Mr Farrell's vehicle, confirmed the fuel had been contaminated.

He said: "We are not saying we know how it got into his tank, but there was definitely petrol mixed into the diesel."

But Shell spokeswoman Olga Gorodilina - who apologised to Mr Farrell for any inconveniences - said the mechanic's word was not enough to point the finger at the fuel giant.

She said it was extremely difficult for customers to establish if a diesel contamination had actually took place, because you couldn't "see or smell it".

She said: "You can only establish contamination by chemical analysis, so even a garage mechanic would not be able to diagnose this."

The company came to this conclusion after conducting a standard fuel quality investigation, she added. "It was revealed there were no other customer complaints and no other discrepancies in delivery documents or stock management.

"If crossover had been the cause, there would be very obvious telltale signs - but there were none in this case."

Mr Farrell, who visited the station on June 8, urged any other affected motorists to call him on 07890 107 933.