Police Commissioner Gary Griffith has reminded companies that the use of blue flashing lights similar to those used by the police can only be authorised by the Transport Commissioner. He warned that a crackdown on unapproved vehicles using these lights was imminent.

Speaking during the weekly police media briefing on Tuesday, Griffith likened the prevalence and use of the blue lights to Christmas trees.

He said even the police had to seek approval from the Transport Commissioner to use blue lights.

But, he said, "What we are seeing now is security companies, even certain organisations in the public sector, from Central Bank security and everybody else, showing a blue light.

"This is going to stop with immediate effect. Police officers have been briefed: we are going to stop all vehicles we see with blue lights and verify if these unmarked vehicles have authorisation from the Transport Commissioner."

Referring to an incident last week when a man was arrested for driving a marked police vehicle as part of an escort for trucks in Tableland, Griffith said the police would deal immediately with such incidents.

What the law says:

The Motor Vehicles and Road Traffic Act Regulation 28, Section (3) says: "The Licensing Authority shall authorise in writing the carriage and use of any siren or warning instrument on any vehicle.

"All transport officers who are in contravention of the use of sirens and warning instruments on their personal vehicle(s) or any other unapproved vehicle(s) are hereby to cease from such practice and to immediately remove such apparatus from the unauthorised vehicle(s)."