Almost 100 ticket touts and hotel fraudsters have been arrested for their part in an Olympics scam.
Home Secretary Theresa May confirmed that police arrested 97 people for selling tickets on the black market, creating fake websites and selling hotel rooms that did not exist.
"We're not going to tolerate intrusions by organised criminals into the Olympic Games," May told the security thinktank Royal United Services Institute in London.
Massive demand for London 2012 will fuel the illegal ticket trade as people scramble to lay their hands on scarce tickets.
The official ticketing system has been controversial as its lottery style has left some fans with multiple tickets while others go without and ticketing blunders have hit the headlines.
A resale of unwanted tickets to the public had to be called off.
Those who were unsuccessful in the original lottery were able to buy tickets for face value from those who no longer wanted or were able to go to events - until the ticketing website crashed.
After days of attempts to fix the website Olympics organisers instead bought up all the unwanted tickets and will release them, alongside the 1.3m tickets left, in a general sale in April.
In another gaffe twice as many tickets were sold as there were seats to a synchronised swimming event.
Scotland Yard is warning people away from the black market, saying action will be taken against those who buy or sell tickets illegally.