Victims of the estate agent

But FPD Savills then sent them a £9,000 bill for calling off the house sale without good reason, warning them they could face court action. Mr Cameron, 46, a TV producer, said: "It is crazy I have to pay a fee for not having my flat sold." The row centred on clause five of the company's terms which states half the sale fee is payable if they find a "willing" buyer. Mr Cameron said: "We did not feel we were getting good advice and regarded the agreement as null and void."

He heard nothing for several weeks and asked for the keys back - but was told there were potential buyers in the wings.

"Then, a friend asked if she could stay in the flat", Mr Marshall said. "Assuming it was still empty, I gave her my keys." The friend found two foreign students living in the flat. They produced a 12-month tenancy agreement, signed a few weeks earlier, which referred to a landlord with a fake address in Chelsea and monthy rent of £650.

Lambeth council's trading standards department prosecuted Lynx, which pleaded guilty to breaching the Trade Descriptions Act. But magistrates fined the company only £500 and costs.

At the time Ms Griggs said the fine "will not deter this and other agents from doing it again". A year later Lynx was prosecuted again - this time ordered to pay more than £14,000 in fines and costs for putting up 'sold' signs outside homes not on the market.

Almost a year to the day after the Evening Standard took up their complaint, Kensington magistrates imposed record fines of almost £12,500 on the company.

In its defence, the Berkeley directors, some of whom were using assumed names, argued that "fly boarding", as it is known, was a common activity and a victimless crime.