Experts have warned that the jamming of satellite-navigation equipment with noise signals is rising rapidly. The hackers have come up with easy ways of jamming GPS signals with cheap gear.

"GPS gives us transportation, distribution industry, 'just-in-time' manufacturing, emergency services operations - even mining, road building and farming, all these and a zillion more", said David Last, a Consultant Engineer and Former President of the Royal Institute of Navigation.

"But what few people outside this community recognize is the high-precision timing that GPS provides to keep our telephone networks, the internet, banking transactions and even our power grid online", he added.

He further explained that the military systems have been unintentionally contributing to this, flooding an area with a signal at the GPS frequency for years, in an effort to frustrate enemy navigation systems. Small jamming devices are easily available online.

Low-power, hand-held versions that cost less than £100 can run for hours on a battery and confuse sat-nav receivers tens of kilometers away.

"You can now buy a low-cost simulator and link it to Google Earth, put on a route and it will simulate that route to the timing that you specify. A GPS receiver overcome by it will behave as if you're travelling along that route", said Mr. Last.

He warned that the criminals are likely to get hold of these tools in next two years, completely.