IT COULD be one of the most bizarre reasons ever offered by a speeding driver - "A ghost made me do it''.

But that is exactly the story being put forward by superstitious motorists hitting speeds of up to 180km/h on a road north of Newcastle, supposedly to conjure a ghost.

Port Stephens police have issued a warning to drivers after it emerged that young people were driving at dangerously high speeds along a stretch of Lemon Tree Passage Rd to conjure the spirit of a 20-year-old motorcyclist killed in a crash with a speeding driver in the area three years ago.

A handful of videos have been posted on YouTube, allegedly showing a ghostly bright light appearing in the rear windscreen of cars that start driving at dangerous speeds.

Some locals are convinced the light is that of the motorcyclist's ghost, in pursuit of people who drive dangerously.

It might sound far-fetched but speeding to summon the ghost has become such a concern that police have issued a warning about the behaviour.

"It's alleged that if you drive at speed in a manner dangerous, a bright white light comes in behind you and that's what they are calling the Lemon Tree Passage ghost,'' a police spokeswoman said.

"There have been several phone calls that people are going out there and while attempting to get footage for YouTube these cars are travelling at excessive speed.''

The YouTube videos posted so far do show a bright light clearly visible, sometimes close to the car and other times in the far distance.

But the source of the light is unclear.

"We want speeding drivers to know that the only bright light they'll be seeing in their rear windows will be the red and blue lights of a police car,'' the police spokeswoman said.

Originally published as Ghost makes motorists hit 180km/h