A FORMER special forces soldier clocked doing more than 80mph at an accident black spot said he speeded up because he thought a submachine gun was being aimed at him.

Gareth Cook, 48, said he reacted instinctively' when he saw the police speed device being pointed at his car. Cook, who said he was trained in anti-kidnap techniques, said he accelerated down the A36 at Thoulstone, where there have been a number of serious accidents.

Unemployed Cook, of Poole, Dorset, was appealing at Swindon Crown Court on Friday against his conviction for speeding. PC George Rabczak told the hearing he was conducting traffic checks on the road at Dead Maids near Chapmanslade on Christmas Eve, 2004.

He said: "It is considered a very dangerous road considering we have had a number of fatal collisions and very serious collisions."

The traffic officer said just after 8.30am he saw a silver Mercedes SLK crest the brow of the hill and realised it was exceeding the 60mph limit.

"As Mr Cook's vehicle came into view the front of his car dipped quite dramatically and in my opinion he was braking very hard to reduce his speed."

The officer used a speed gun, which registered the car at 81mph. He was tried and found guilty at Chippenham magistrates' court in his absence in October 2005 and fined £300 with £280 costs with three penalty points.

Giving evidence Cook said that he believed that the speed gun might not have given a correct reading because it was close to a 3G mobile phone mast.

But he admitted he may have been speeding on the dual carriageway section of road before he came over the top of the hill. Conducting his own case Cook produced a head on picture of an Ingram sub machine gun, which he said was a favourite weapon with drugs gangs in Nottingham and suggested it looked like the speed camera.

"I came over the hill with the sun in my eyes and saw a dark car with two men in it aiming a gun at me and I reacted instinctively," he said.

"As I said I was in special forces and trained in anti-kidnap, hostage release and I have done the lot as far as driving. "As soon as someone is pointing a gun at you, you put your foot down."

Under cross-examination by Joanne Lucas, prosecuting, he accepted that the reading may have come when he accelerated after seeing the speed gun.

Judge Charles Wade ordered Cook pay a further £120 in costs giving him a year to pay the £700. The three points will also go on his licence.