The epidemic of stolen portable sat-nav units has reached such large proportions that car security firm Tracker has teamed up with the police to catch thieves using technology James Bond’s Q would be proud of.

The firm’s special operations division has built dummy sat-nav units that incorporate a tracking device so that thieves stealing them from cars can then be tailed and caught by the police.

Portable sat-nav units were now the single biggest target in cars for thieves, with figures from Autoglass suggesting that smash-and-grab raids had increased by a fifth this year alone as the systems become more popular.

The problem is so widespread that police forces throughout the UK have resorted to sting operations to catch offenders with the help of Tracker, which has just celebrated a major milestone by recovering more than £300 million-worth of stolen vehicles since it started trading in 1993.

Parita Patel, marketing manager for Tracker, said: "Tracker’s unique Stolen Vehicle Recovery technology is unsurpassed. We have an extremely close working relationship with the police and we do all we can to help the fight against crime. For obvious reasons, little is known about our special operations division, which the police call upon to develop a variety of systems to help catch thieves redhanded.

"The specially-adapted satellite navigation systems have been thoroughly tested and, like any vehicle fitted with a standard Tracker system, can be traced with pin-point accuracy."

PC Jane Jepson, crime prevention officer for Staffordshire, the first police force in the UK to use the units, said: "Portable sat-nav systems are the must-have motoring gadgets of the moment and their thefts have risen to an epidemic proportion.

"We recognise that something drastic needs to be done to tackle the situation and so approached Tracker for assistance.

"Hopefully, with their help, we will be able to catch the criminals who target these devices red-handed."