A WATCHDOG has demanded new safety standards are put in place after a North Wales Police officer, driving an unmarked vehicle whose lights were covered by tights, was seriously injured in a collision.

The Independent Office for Police Conduct (IOPC) carried out an investigation into the incident which took place early in 2016 and was partly blamed on the front grille of the BMW being covered by tights to mask the identity of the car.

Officials found the levels of brightness of the BMW, which collided with a HGV lorry in a layby, was "significantly reduced" by the method and could not rule it out as a contributory factor in the crash.

They concluded that it made it extremely difficult for the driver of the HGV to identify the vehicle behind them as a police car responding to an incident.

Now national guidance will be developed to standardise the practice of covering emergency blue lights on unmarked police vehicles.

North Wales Police say the modification was not standard practice and was stopped immediately the Force became aware of it.

An IOPC spokesman said: "A North Wales Police officer, who was driving the police BMW, was seriously injured as his car collided with an HGV in a lay-by. He had attempted to avoid a light goods vehicle which had moved into his lane on a dual carriageway.

"Emergency lighting in the front grille of the BMW had been covered with tights to help prevent members of the public identifying it as a police car when the lights were not in use. It was found that there was a significant reduction in the light output with the nylon covers."

The watchdog found that a number of police forces are using various methods to mask unmarked vehicles, including using nylon tights. But the modifications are being made without any form of scientific testing to examine their effects.

IOPC Director for Wales Catrin Evans added: “When police forces attempt to make unmarked police cars less visible, they need to adopt a standardised approach.

“Any modifications made ought to be tested and approved by experts rather than using ad hoc solutions that may not be the safest method. For the safety of police drivers and the public alike, testing would also help make sure that any coverings do not significantly limit the visibility of the emergency blue lights."

The IOPC has made its recommendations to the National Police Chiefs’ Council (NPCC) which has commissioned a working group to produce new guidance.

North Wales Police's professional standards department became aware of concerns surrounding the North Wales collision in February 2017, a year after the incident.

The IOPC said that it found no case to answer for the officers involved in covering the grille lights with tights due to the lack of any national guidance. No members of the public were harmed in the collision.

North Wales Polices Deputy Chief Constable Richard Debicki said: “Officers concerned about the identification of unmarked cars by the emergency lights made the modification. However, there was no national or local policy in place at the time and the IOPC is very clear that there is no case to answer for any officers in this case.

“However, the organisation has learned from this experience and necessary changes were made forthwith and the practice stopped immediately. The clear instruction now, therefore, is that the lights must not be obscured in any way.

“The development of national guidance is particularly welcome, as this was clearly an issue affecting a number of forces."