A serial motorbike thief who scours newspaper adverts for potential victims has now struck six times in the past three months.

Sussex Police are urging bike owners to be on their guard to prevent the conman claiming any more victims.

The thief has duped bike owners in Polegate, Bexhill, Worthing, Peacehaven, Burgess Hill and Storrington.

So far, the victims have included an engineer, a tax inspector, an electronics engineer and a fire officer.

Each time, he answers adverts in the Friday Ad newspaper, gains the confidence of the seller, displays a knowledge of bikes and disappears while on a test run.

He leaves what appears to be his own bike behind with the key but, in each case, the bike has belonged to his previous victim.

And, as well as causing upset and anger, the thief's actions have caused even more misery for one victim.

Alan Bryant, whose £2,950 T registration Yamaha Fazer was taken from his Burgess Hill home, was delighted when police found his bike.

But he has been told he must pay £105 before they will release it.

Mr Bryant said: "I was told by the police they wanted to keep it for finger-printing, which I thought fair because this thief must be caught.

"The next day, I received a letter saying I will have to pay £105 for storage purposes and £12 a day for every day it is left in the pound.

"They could have finger-printed the bike at the house where it had been left, without taking it to Shoreham."

Police say the cost can normally be claimed back on insurance.

The thief first struck on June 22, when he arrived at the Worthing home of engineer Clive Lewis, who was selling his £3,000 Suzuki bike.

He left behind a Kawasaki worth about £1,500.

He spent three weeks riding the Suzuki, clocking up more than a thousand miles, before turning up at the Peacehaven home of Ed Knight.

Mr Knight thought nothing of letting the biker go for a spin on his £3,000 bike, as the thief left behind the Suzuki.

But realising his NX 650 Dominator had been stolen, Mr Knight contacted The Argus in order to warn bikers not to be taken in. Despite this, Mr Bryant was conned next and then the thief struck again - arriving at the Storrington home of a West Sussex fire officer last weekend.

He left Mr Bryant's bike and disappeared on a gold W registration Yamaha Fazer.

Police have not released details of last two thefts, in Polegate and Bexhill.

On each occasion, the bike is returned in perfect condition, with evidence of it being kept in a garage and proper maintenance and cleaning having been carried out.

The thief was described as 5ft 11in, between 30 and 35, of stocky build with short cropped blond hair. He has been seen wearing a black and blue Arai motorcycle helmet.

One victim described him as "a softer version of the character Grant Mitchell from EastEnders."

A police spokeswoman said: "We are very keen for anyone who recognises him to get in touch with us."

Call Sussex Police on 0845 6070999 or Crimestoppers on 0800 555111.