Detectives say many websites intended for use to commit fraud are using imagery of Olympics to lure customers

Detectives from the UK's leading cyber crime unit have identified hundreds of websites that could be used to dupe visitors to next year's London Olympics.

They have already closed around 2,000 sites set up by criminals and purporting to sell luxury goods, and are monitoring hundreds of others that have popped up on the web with the games in mind.

Some are using the event's signature image of five Olympic rings, which could lead people to believe they have official endorsement.

"We think there is some evidence to suggest they are waiting to commit fraud," Janet Williams, the deputy assistant commissioner at the Metropolitan police, said. "These websites have been set up and are in a holding position, and we will monitor them to see if they are used for criminal purposes."

Williams, the head of the e-crime unit, said ticket fraud was just one way criminals would try to exploit the games.

"We would be naive to think that it would be the only threat during the Olympics," she told the Guardian. Her unit, which has a staff of 106, is working with other agencies, including the government communications headquarters GCHQ, to intercept traffic that might point to an attack on London's infrastructure. Attempts to cause disruption through "denial of service" attacks have become a common tactic for hackers.

"The issues we are planning around include a [possible] attack on the transport system ? but we have to be flexible. During the planning for the general election, we looked at all the potential things that could happen, and went through a range of contingencies. But nobody thought about a volcano erupting in Iceland." The Met itself has come under cyber-attack, and Williams said the force had now beefed up security around its computers.

The Olympics is one area being overseen by the e-crime unit, which has been expanding to try to meet the huge scale of online crime. It is setting up three satellite hubs covering the north-west, Yorkshire and Humberside and the east Midlands, and estimates that in six months this year its virtual taskforce prevented crimes that would have otherwise cost ?140m.

The unit also prevented a cyber attack on the Clarence House website. The planned attack had been designed to stop a live video screening of the royal wedding in April.

"It will be a big step up for us to have a regional capability," Williams said. "There will be a small number of people in each hub, and for major events, like the Olympics, we will work together."

She said there is some evidence that "old school" crime organisations are moving into the cybersphere. While these groups will attempt to operate across international boundaries, many are based in the UK.

"They are learning fast and developing their capabilities fast," she said. "When we first approached this we wondered whether we would be looking at criminals in other countries ? we are looking at criminals here in the UK."