Internet conmen are targeting Oxford in a new scam to fleece thousands of pounds out of househunters.

In the past month, a dozen people have been swindled out of about £800 each after sending deposits via money transfer for accommodation advertised to rent on websites www.oxford.gumtree.com or www.dailyinfo.co.uk More than £8,000 has been handed over. Fraud officer Pc Claire Beach said she believed this could be just the tip of the iceberg.

She said: "The alleged landlords are very insistent that before the place is viewed, a deposit must be sent via a money transfer company.

"What this means is the money is untraceable and investigating it afterwards is very difficult because it is picked up as cash and then vanishes into the ether."

Fraudsters emailed the victims over several days, giving plausible reasons why they could not view the property first.

Pc Beach said: "I would imagine there are people who have not contacted the police because they are embarrassed.

"If you go on to the gumtree site, they give you ideal or safe ways to pay and there are warnings about sending money via money transfer, and there are also warnings in Western Union offices saying you should not send money to people you do not know."

Nine of the victims were targeted through Gumtree, and one via Daily Info, with properties advertised in East Oxford, Summertown, Oxford city centre, and one in Abingdon. Two more have come forward, said Pc Beach.

Clare Cochrane, 37, of Warneford Lane, was contacted by two apparent fraudsters after putting an advert looking for a room on gumtree.

She said the offers seemed "too good to be true" but she decided to look into it.

However, after she refused to send a deposit via Western Union, they broke off contact.

She said: "It's like online dating in that you have to protect yourself and never send money until you have signed the contract or are signing it."

Oxfordshire County Council's trading standards department was made aware of a similar scam two months ago - the first it had heard of in Oxford.

Spokesman Richard Webb said: "It's something we and the police will be investigating. We will also be talking to the universities to make sure they are aware as students are one of the most at risk groups."

Gumtree spokesman Katie Davies, said: "We actively discourage users from transferring money in advance of seeing a flat.

"There's simple, useful information about how to stay safe on the site and we also encourage users to share their own online experiences and advice."

A spokesman for Daily Info said: "All our sales and accommodation pages link to our advice on scams and fraudsters and we advise all our users to read these pages and also to familiarise themselves with certain specialist scam-watching websites."