It's common courtesy when we spot a speed camera to warn many oncoming drivers who can slow down to approach with care - and many of us practice it.

But next time you flash your lights to warn others of a police camera - think twice, because you could be committing an offence and by doing so, could get slapped with a fine yourself, according to ChronicleLive.

The Highway Code, under rule 110, states: “Only flash your headlights to let other road users know that you are there.

“Do not flash your headlights to convey any other message or intimidate other road users.”

But if drivers do choose to flash to warn others about a speed trap implemented by the police, they could be in breach of section 89 of the Police Act 1997 .

Under this law it states that it is an offence to 'wilfully obstruct a constable in the execution of his/her duty'.

Therefore police could charge anyone who appears to be obstructing their ability to conduct speed checks on other motorists, with this criminal offence.

The maximum fine for obstructing a police office is capped at level three on the fine scale, with a maximum penalty of £1,000.