Police have renewed their appeal for help in tracing a savage road rage attacker who slashed his victim's arm and face on a quiet, foggy road.

Investigations into the attack nine months ago have failed to track down the crazed driver who used a four-inch knife on his victim.

The attack happened on the A68, between Darlington and West Auckland, in County Durham. The 26-year-old victim was overtaken on a bend by a car which had sped up behind him in a matter of seconds, at around 12.45am on a Wednesday morning in May last year.

He flashed his lights in annoyance and sounded his horn, and the other driver slowed down, stopping his car on an angle, to block the victim's carriageway.

When the drivers of both cars got out, the attacker cursed his victim and attacked him with his fists and the knife before coolly returning to his small, off-white Peugeot-style car and driving off.

The victim was able to drive to a lay-by and call for assistance using a mobile phone. The incident happened between Toytop Farm and Sunnydale Farm and the suspect was described as in his 30s, male, white, about 6ft and of stocky build. He had short, dark hair and two or three gold-coloured hooped earrings in each ear.

Last night, Detective Sergeant Alec Francis, of Darlington police, said officers were ready to act on any new information received about the attack.

He said: "It's still an outstanding incident, the offender has never been caught. "We would respond to any information in relation to the attack."

Anybody who has any information is urged to contact Darlington police on (01325) 467681 or Crimestoppers on 0800 555111.