Estate agents desperately turn to illegally hijacking properties for sale off the web

An investigation by the BBC's Money Programme exposed a London agency, Amelia King, which advertised a property without the vendor's permission or knowledge - and at more than his asking price.

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The practice is a criminal offence, in breach of the Estate Agents Act. A successful prosecution could result in a fine of up to £25,000.

To avoid the commission charged by estate agents, Simon Holder offered his Greenwich home for sale privately through Propertybroker.com.

He provided a description of the house, Propertybroker took photos of it, and these appeared on thewebsite.

But Mr Holderwas shocked to learn the property was also being marketed by Amelia King on estate agents' website Rightmove - even though he had never spoken to the company.

His description was used word for word with the pictures from the Propertybroker website. After the Money Programme found two similar cases, he called the agent to ask where it had found his property's details.

Mr Holder, who recorded the call, was told: "I got it from Propertybroker and I was just advertising your property and finding the customers."

The agent agreed that it was not instructed to advertise the house.

Mr Holder also asked why his home was listed at £378,000 when his asking price was £370,000. The agent said this was because it was trying "to find customers free of charge to the owners".

However, the extra £8,000 was just over two per cent of his asking price, an agent's normal commission.

Worse, as his house is now under offer, his buyer would be upset to find the house still on the market.

Amelia King manager Anton Mara was not available when contacted to ask why his company was marketing the property and others without the owners' permission, in breach of the Estate Agents Act. He did not return telephone calls.

Miles Shipside, of Rightmove, said: "If agents are not complying with the Act then it will be our policy to suspend them from membership. That appears to be the case in this instance and that's what we've done."

Kay and Keith Davis, who run Propertybroker.com and have saved customers as much as £82,000 in agents' fees, said: "This is not the first case we know. This offence is widespread and becoming more so as the market gets increasingly competitive. It must be nipped in the bud.

"We are reporting Amelia King and Rightmove to Trading Standards and will strongly urge them to prosecute."

Legislation coming into effect in spring 2008 should stop the practice by requiring all agents to belong to the Ombudsman's redress scheme, which Amelia King does not do.

However, the programme concludes that with the number of private sales websites rising - helping to save sellers thousands - and the public's lack of faith in estate agents, the fight between the two will only intensify.