The promise of a free next generation iPhone being used to gather email addresses and other personal information.

IT security firm Sophos has said that cyber criminals are using the promise of an iPhone 4G (which hasn’t even been announced yet) in exchange for personal information.

"Even though it hasn't been officially announced by Apple, and may not be released for a couple of months, there is a lot of buzz on the internet about the iPhone 4G," said Graham Cluley, Senior Technology Consultant for Sophos.

"In their excitement, some internet users might blindly hand over their personal information in the belief that they will get a preview version of what will be one of 2010's hottest gadgets. But being careless with your data risks exposing yourself to more spam in future and costly identity theft."

Sophos also says its researchers have uncovered a co-ordinated campaign on Twitter, using avatars of young women and adverts promising a "free iPhone 4G" in an offer that is claimed to end today.