IT is roughly the size of a matchbox and weighs less than an ounce. But an electronic tracking device could ease the fears of parents worried about their children going missing.

The £500 bug, made by Tyneside firm GlobalPoint Technologies, enables parents to keep tabs on their youngsters via the Internet using satellite tracking technology. The device was developed by former electronics experts with the Government's GCHQ spy centre.

It can be monitored for up to 30 hours before its battery needs recharging.

It even contains a programmable panic button on the side of the unit which can send instant position reports.

John Davidson, of GlobalPoint Technologies, said: "You can put it in your pocket and be pinpointed to within two metres of where you're standing.

"You can find it on the Internet or you can use it via mobile telephone and send it a text message asking where it is."

The device does not work as effectively if someone is inside a thick-walled building or if there is no mobile phone coverage. But Mr Davidson said future models would be more sophisticated.

A larger, cheaper version has also been created, suitable for tracking stolen plant hire equipment or caravans.