Norfolk Police have launched a crackdown on the growing number of drivers who are using laser jamming devices to disable speed guns.
Motorists are being warned they could face prosecution for obstructing police. Speeding drivers will end up paying fines and having points added to their licence, which could send their car insurance premiums soaring.
A laser jamming device, which can be installed for around £355, notifies drivers about speed detectors in the vicinity and allows them to slow down while it temporarily stops the sensors from functioning.
The gadgets are not illegal per se, but blocking police speed guns is a punishable offence, traffic officers said.
Recently the driver of a Mercedes travelling towards Great Yarmouth was arrested on suspicion of perverting the course of justice after police were unable to obtain a speed reading from the car.
The 57-year-old man, the sixth motorists to be held for using a jamming device, has been released on police bail until October 2.
It is one of five cases being pursued by police and follows a successful prosecution in July where a driver was given a six-month conditional discharge and fined £85 after he admitted using a laser jammer for obstructing police.
© Press Association 2010