Online opportunists are attempting to cash in on Londoners looking for information on the three main candidates in this week's Mayoral election.

Cyber-squatters have registered dozens of key domain names relating to Ken Livingstone, Boris Johnson and Brian Paddick.

Pay-per click ads on the bogus sites are designed to make money from unsuspecting visitors.

Liberal Democrat candidate Brian Paddick has encountered minimal cyber-squatting, despite hiring US 'blogfather' Jerome Armstrong in a bid to beef up his online campaign.

Ken Livingstone and Boris Johnson are the subjects of most of the cyber-squatting activity, but speculators are targeting the two main candidates in very different ways.

Livingstone has been the subject of much negative cyber-squatting, including the registration of domains such as ihatekenlivingstone.org and kenlivingstone.org.

The latter boasts an image of Livingstone as a cowboy and the headline 'Do you really want to pay for Ken Livingstone and his cronies?'.

However, the Boris Johnson sites have tended to be straightforward 'click farms' that feature pay-per click advertising to make money from unsuspecting voters.

Domain management company NetNames believes that The Tories have learned from previous negative experiences such as the well known spoof of David Cameron's video blog 'Web Cameron' created by Labour MP Sion Simon.

"With high-profile London candidates like Ken Livingstone and Boris Johnson, cyber-squatters are bound to be waiting in the wings to register campaign-relevant domains," said Jonathan Robinson, chief operating officer at NetNames.

"It is very hard to stop negative websites and click farms springing up but, by leaving obvious domains unregistered, the candidates have provided a route for cyber-squatters to make money from unsuspecting voters."

Boris Johnson seems to be the most proactive of the candidates at protecting his brand online. More than 10 related domain names all point to his official site.