There are calls to ban a new device that alerts drivers to nearby police cars.

Britain’s police watchdog and some motoring groups says that the Target Blu Eye gadget is illegal and should be banned.

The device shows a series of flashing lights to warn a driver a police car or even helicopter is nearby, showing its proximity and relaying radio signals from an officer on the beat.

Those opposed fear the device will be exploited by speeding motorists and criminals, while some argue it may actually have safety benefits.

Target Blu Eye can detect an emergency vehicle around a kilometre away, by picking up their encoded radio signals

One company that sells the device claims it is meant to allow drivers to get out of the way of fast-moving emergency vehicle, thereby assisting safety.

The UK Government is looking into claims that it breaches the Wireless Telegraphy Act, which governs the use of radio communications.

“This device is a passport to villainy and there is no legitimate reason for a law-abiding person to have one,” said Ian Johnston, a county crime commissioner.