The frequencies used by GPS systems are being jammed routinely in the UK by individuals attempting to block the location tracking systems used by delivery trucks and anti-theft systems, a new study has found.

Funded to look into the issue of GPS interference in a systematic way by the Government’s Technology Strategy Board, the Sentinel project discovered evidence of a surprisingly large underground of GPS jamming across the country after starting monitoring in January 2011 using a network of 20 road sensors.

One of the sensors by a busy motorway recorded more than 60 jamming incidents over a six-month period around the 5GHz band reserved for GPS, with the project detecting an around ten per month across the whole network.

Although these numbers sound small, they offer a tiny window a problem that must on the basis of only a handful of sensors be far larger.

GPS jammers that plug into 12 volt vehicle outlets are cheap and easy to obtain, but the growing extent of their use has not been reliably documented until now. Exactly who would be interested in using them is hard to know although the two most likely culprits are van drivers attempting to defeat their company’s GPS-tracking systems as well as vehicle thieves.

Growing use of GPS jamming would have a negative effect on legitimate users, with signals masked for 200-300 metres around each moving device.

"The next step is to develop the system further so that it can be used for enforcement, so that you can detect a jammer in use and then relate it to the driver that's using it," Charles Curry of Chronos Technology, which is running the project, told the BBC.

The GPS satellite system was built by the US during the 1980s for military purposes before being made available in a less precise version for civilian uses later on.

It remains the dominant navigation technology in the world despite rivals such as the European Space Agency's Galileo network having nipping at its heels. Galileo is not expected to start operation until 2014.