A man selling a superbike looked on in disbelief as a prospective buyer stole it during a test ride.

Maraouan Anzaoui, 41, posted an advert on online listings site Gumtree, intending to sell the �4,000 Yamaha YZF-R1 before moving back to his native Greece.

He responded to interest in the bike from a man in Barking and Dagenham and agreed to meet him at around 7.30pm on October 8, hiring a van to bring the bike from Greenwich with two friends.

After a cautious agreement to allow the buyer a test run, Mr Anzaoui looked on helplessly as the 1000cc bike, along with the supposed buyer, disappeared down an alleyway in Cotton Close, Dagenham, and out of sight.

He said: “I just gave the bike to him. I don’t do that, I don’t know why I did it. I always have my guard up, my whole life, and this guy made all three of us look so stupid we didn’t even say a thing.

“When he drove away he was going really slow and then just disappeared. It is like we were blind for a couple of seconds.”

Mr Anzaoui, bar manager at the Fakhreldine restaurant in Mayfair, had saved for three years to afford the bike which he purchased only three months ago.

“I feel awful,” he said. “I would prefer it if (the theft) was from my back-yard instead of me giving it to somebody who rode off with it.”

Mr Anzaoui is offering a �1,000 reward for the safe return of the motorbike, which carries the licence plate FP04 FML.

A Gumtree spokeswoman said: “We take this type of issue very seriously and are 100 per cent committed to the safety of our users.

“We actively encourage people to act with care and caution when meeting with prospective buyers and sellers and publish a range of practical and useful tips on the Gumtree website to help ensure the safety of our users.

“We would always recommend that if a potential buyer requests a test drive of a vehicle, the seller requests photo ID so they have their details and that the seller takes a security deposit.”

Police confirmed they are investigating the theft of the motorbike from Cotton Close at 7.30pm on Monday October 8 and that enquiries were ongoing.

Anyone with information should call police on 101 quoting crime reference number 5117273/12.