Fraudsters are planning to exploit the public’s newfound enthusiasm for the Olympic Games in London three years before tickets go on sale.

An American lawyer representing 144 victims of a fake ticketing scam during the Beijing Games — the victims of which included the parents of the double Olympic swimming champion Rebecca Adlington, who paid £1,100 for tickets that never arrived — gave warning that the syndicate behind the crime would repeat its multimillion-pound swindle in 2012.

“I was shocked by the brilliance and hard work of the thieves fleecing the Olympic family — and they are setting up to do the same thing

in Vancouver in 2010 and London in 2012,” Jim Moriarty, a Houston-based corporate lawyer, said.

Beijingticketing.com was the main vehicle for an online fraud by a company called Xclusive Leisure & Hospitality, which is now the subject of legal action by the International Olympic Committee.

Security experts have closed down sites illegally using Olympic brands, including the 2012 logo, and are on constant watch for new ones. About 25 known e-mail, postal and telephone stings have been halted, including an unauthorised Olympic lottery, a fake promotional draw using the names of a 2012 sponsor and senior London officials, and a false grant scheme. However, advances in technology are making it easier to bypass online security.

Mr Moriarty, who was himself conned by the bogus site that looked so professional it fooled the experts, hopes to secure criminal prosecutions by posting the results of his own investigations on his website, beijingticketscam.com. His list of the 250 web domain names bought by Xclusive includes four related to the winter Games in Vancouver and one — london-tickets.net — that could be used for the 2012 Olympics.

“The British authorities have known about these guys for years. I have given them the tools to track them down. Let’s hope they’re smart enough to use them,” he said.

London organisers are drawing up their ticketing strategy. The contract is expected to be awarded to Ticketmaster.com, according to industry sources.