Mobile phone users are being warned about an email in circulation claiming that their handsets could be taken over.

The emails, purporting to come from Hampshire Police, state that fraudsters can take over a Sim card simply by getting the phone user to press three buttons. It also claims that a mobile virus called Xaxalan can be picked up just by answering a call.

"This is not one of ours," said a spokeswoman from Hampshire Police. "We would never send out that kind of email. It's possible someone's got this from a friend in the force but if that's the case it isn't endorsed by us."

A similar email, circulated five years ago, highlighted a genuine problem with US mobile phones. The addition of a mobile phone virus paragraph looks to be more recent.

"The reason that chain letters and hoaxes like this continue to live is because it's so easy to forward a warning to all your friends and colleagues via email," said Graham Cluley, senior technology consultant at Sophos.

"People's 'quality control' and cynicism reduces because it's no effort to pass it on. It's so easy to forward to everyone that people do it 'just in case'."