The hoax e-mail - signed "from the Safeway team" and headedwith the company's e-mail address - announced a 25 percent price increase and told customers that if they were unhappy they should shop at rivals Tesco or Sainsbury, the newspaper said.

"The message does seem to have been sent out by our owncomputer system and we're trying to track the source," a Safeway spokesman told the newspaper. "We are investigating whether the computers may have been hacked from outside or whether there may be an internal source."The E-mail is the latest incident to expose Internetsecurity failures in Britain.