Apple has begun work to address a potential security problem with iPhones' text messaging system.
The potential security breach followed the discovery of a flaw in the SMS system that may allow hackers to gain access to the mobile phone's GPS features and track its location.
In turn, fraudsters could then remotely activate the microphone to listen in on conversations.
More worryingly, the iPhone may also be transformed into a botnet. This would clear the way for it to send spam and be used to commit fraud.
The potential for the flaw to be exploited by criminals was outlined in an address by a security researcher last week at the SyScan conference in Singapore.
Charlie Miller said: “I can definitely make the thing crash. I have still to determine whether it’s actually exploitable or not.
“This thing has the potential to be really serious, but I’m still looking at it and Apple is still looking at it.”
Mr Miller is expected to expound further on the iPhone’s vulnerability at a Black Hat presentation due later this month.
It is thought that the problem applies to all Apple handset models, including the latest edition, the iPhone 3G S - widely regarded as the best mobile phone to be launched so far this year.