Robert Bennett’s Suzuki Hayabusa motorcycle, one of the fastest machines on the road, capable of speeds of 220mph, was barely straining when he overtook a police car.

Unfortunately for him, the bike was making such a racket that the police officer inside the car turned on his speed camera and caught Bennett doing 122mph, more than double the 60mph limit.

Clinging to the pillion as Bennett accelerated into a blind spot in wet conditions in April last year was his 14-year-old son, Russell, whose glove-less hands are clearly visible in images from the speed camera.

Bennett paid the price for what a judge called unbelievably irresponsible driving when he was sentenced at Exeter Crown Court to six months in prison.

Bennett, 47, a cleaning supervisor from Barnstaple, North Devon, had collected his son from the home of his former wife and was heading back to Barnstaple on the A361 near Swimbridge.

Lee Bremridge, for the prosecution, said that a police officer heard the sound of the bike “accelerating hard and revving its engine”.

He said: “He turned on the speed camera and captured Mr Bennett powering past them. The police officer formed the opinion that the defendant was riding dangerously.”

Bennett was traced through the registration number and initially denied being on his bike that day. He changed his mind when he was shown the footage from the speed camera. “He could not believe that was how fast he was going. He was remorseful,” Mr Bremridge said.

As Bennett pleaded guilty to dangerous driving, Judge Phillip Wassall told him that he would serve at least half his sentence as a warning to others.

He said: “Had you lost control of your motor cycle it would have become a missile, causing a serious accident and probably the death of at least one person.

“The aggravating feature of this case is that you had your 14-year-old son on the back of the bike. He was on a contact visit from your estranged wife and your lack of responsibility is almost unbelievable when considering the impact any accident would have had on her and her family as well as your family.

“This was so dangerous that I cannot ignore it or avoid an immediate prison sentence and I have to send out a message to others.

“At the time you were doing 122 miles an hour in a 60 [mph] limit, the road was wet and you were on a bend. If you had burst a tyre or someone coming the other way had pulled out, you would have lost control of the bike.”

David Sapiecha, for Bennett, said that his client had been riding motorcycles for more than 30 years and had not been drinking or taking drugs. “The dangerous aspect of the motoring was the speed and the fact that he had his son with him.

“It was an out-of-character offence over a short distance and his behaviour that day was unusual.”

Bennett had boasted that his 1300cc Suzuki was one of the fastest motorcycles on the road.

“I hold my hands up. I was doing 122 mph on that road and that was dangerous, especially with my lad on board. But it had started to rain and I pulled back the throttle.”

Natalie Hatswell, communications manager at the Devon and Cornwall Safety Camera Partnership, said: “We are all responsible for the speed at which we drive and ride. Those who choose to travel at excessive and inappropriate speeds not only risk their own lives but also the lives of others. In this case, that also included the rider’s own 14-year-old son.”

Bennett was also banned for 18 months and will have to retake his test to get his licence back.

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