A thief who stole a motorcycle during a test drive has struck again, dropping off one stolen bike and driving off with another.

He appears to be making a habit of his scam and is getting away with riding around on other people's bikes.

Police are warning motorbike enthusiasts to be on the lookout for the serial thief, who answers motorcycle adverts in the Friday-Ad newspaper, asks to take the bikes for a spin but then rides off.

The thief is now swapping a bike a week.

At least three bikers are amazed they have been taken in by the test-drive con.

Motorcycle enthusiast Edward Knight, a tax inspector, was livid when he was conned by the thief.

In The Argus on Tuesday, he alerted other bikers.

However, Mr Knight has now got his bike back as the thief calmly left it with another seller while carrying out the same trick.

Unfortunately, Alan Bryant, 36, had not seen Mr Knight's warning.

The thief left a bike with Mr Bryant when he rode off, which turned out to be Mr Knight's.

When Mr Bryant, of Burdocks Drive, Burgess Hill, phoned police, they knew immediately he had become the latest victim of the test-drive thief.

Now Mr Knight has his Dominator £3,000 NX650 bike back, while Mr Bryant is missing his Yamaha Fazer 600, which he had advertised for £2,950.

Mr Bryant, an electronics engineer, who is married with two young children, said: "I am not the kind of person that is usually taken in by a con such as this. He seemed a highly pleasant, plausible chap who knew about bikes.

"He knew all about the Fazer bike and said he was selling the Dominator because it was a sports bike and you had to ride it in a racing position and it hurt his back. My Yamaha is more of a sit-up bike. It seemed to be a perfectly good reason.

"We discussed the bike and chatted. I even got to know he was with a partner and had two dogs, which I joked were easier to look after than children. The guy was not nervous and did not arouse any suspicion.

"He asked if I could take it off the stand in case he damaged it, which I thought was considerate.

"As he went off on the test drive, he did not race off down the road or anything like that.

"After half an hour I thought he might have fallen off or had an accident but as time went on, I realised he must have gone off with my bike and left a similarly priced one behind.

"I am pleased Mr Knight has his bike back but now I am the one who has lost out.

"Goodness knows what this fellow is playing at."

Now Mr Bryant is appealing for the return of his black bike, registration number T988 NGP, and warning other bikers to beware of the scam.

Mr Knight said he was over the moon to get his bike back.

He said: "I am ecstatic. It is in perfect condition. It has only done 160 miles. The bike has obviously been garaged as there were no rain marks on it.

"The whole scenario is very weird. Where is he going to strike next?

"I can understand how Mr Bryant got taken in, just like I did.

"There was no doubt in my mind he would return."

The thief is in his early 30s, well-spoken and has short black hair. He wears a black leather jacket and trousers.

Anyone with information should phone 0845 6070999.