A driver who was pulled over by police on a notorious stretch of Norfolk road was found to have a �3,000 piece of equipment that could jam their speed gun.

An officer's laser gun made high-pitched bleeps and was left with a blank screen as an Audi A5 Sport he suspected of speeding drove past him on the A47 near Blofield, a court heard yesterday.<15>

When the driver was stopped, he was found to have a system capable of temporarily jamming the laser and completely erasing the software responsible for it.

Kris Hemsley, 32, pleaded guilty at Norwich Magistrates Court to obstructing a police constable in the course of his duty.

District judge Philip Browning fined Hemsley, of Norwich Road, Acle, but issued a warning that drivers could face disqualification if they used similar equipment in their cars.

Judge Browning said: 'I must say that anyone who installs or has installed this equipment must do so at their peril and risk disqualification from driving.

'In the future the court will seriously consider disqualification in this type of case.'

The court heard that PC David Carter had tried to check the speed of two vehicles travelling along the A47 near Blofield towards Acle on Saturday February 12.

PC Carter said the first was travelling at 57mph in the 50mph zone and he believed the second 'to be of greater speed'. But when he pointed the laser at the black Audi A5 Sport, the laser let off a series of high pitched beeps.

He tried it on another approaching car, which worked, and when he returned to Hemsley's car it gave a reading of 47mph.

He radioed his concern to a colleague, PC Woodrow King, who pulled Hemsley over.

PC King explained he saw three diodes on the front of the car and a control unit near the gear stick. Later investigations found a laser analyser box.

PC King said: 'I have seen car laser jamming devices before but nothing even close to this.'

Sgt Geoff Bowers, who is involved in researching laser jamming systems, said the equipment, a DSI Stinger, was capable of jamming lasers for six seconds. He said this software had an easy-to-use erase facility that could completely remove the downloadable optional extras so that they could not be traced on the system.

Kevin Eastwick, prosecuting, said Hemsely had been interviewed for 20 minutes in Great Yarmouth police station but replied 'no comment' to 13 questions.

Dave Foulkes, in mitigation, said DSI stood for driver safety interface and it had a range of functions with the laser diodes on the front alerting fellow users of the system to heavy braking if nearby.

He said external factors could have affected the police device and subsequent police tests could not show that the laser jamming worked.

He said: 'There is no evidence that particular extra was functioning on this particular day.'

He added that it could also not be proved that Hemsley erased the function.

Hemsley was fined �500 and ordered to pay �240 costs and a surcharge of �15. His equipment was also forfeited.