Disgruntled former staff and customers are behind the wave of computer hacking crime suffered by UK businesses.

Leading fraud solicitors Philippsohn Crawfords Berwald said Harrods' and Land Rover's websites have both come under attack from hackers that have posted offensive material on copycat sites. Surfers searching for links to these bona fide websites have instead found references to sex, drugs and hate mail. In the Land Rover case, the false site gave 10 reasons why the hacker did not like the car manufacturer.

Saboteurs are often ex-employees with access to passwords or aggrieved customers.

Steven Philipsohn, senior partner in the company, said: "The internet provides a wealth of opportunities for illegal activity, including fraud, defamation, and vengeful acts of damage and corruption."

But tracing the perpetrator of cyber crime is possible, allowing assets to be seized, premises searched and losses recovered.