However, users on Microsoft Windows systems risk running the malicious code and infecting their computer, according to a posting on IT forum, DaniWeb, where the problem was first reported.
The units are infected with two trojan viruses, manufactured between September and November last year and shipped with software version 6.51, the DaniWeb entry said.
TomTom would not reveal the exact number of products infected and is yet to issue an advisory to its customers despite acknowledging the incident.
According to the internet posting, when a user contacted the company to report the problem they were advised to “let their anti-virus software delete the virus and move on as they are not dangerous trojans”.
In October last year a number of Apple Video iPods were shipped containing the Windows virus, RavMonE.exe, thought to be infected during product testing. In the same month, a Japanese branch of McDonalds had to recall 10,000 MP3 players after finding spyware installed on the devices.