DURHAM Police last night referred itself to the Independent Police Complaints Commission amid growing criticism of its failure to prosecute a PC reported for speeding at 140mph by the prisoner he was transporting.

The officer's behaviour was yesterday condemned by road safety charities who said officers who break the law should face legal action.

But Durham Police said the unnamed PC escaped prosecution because he was a “highly skilled driver” and the car was “not driven dangerously”.

The Northern Echo revealed on Friday how the 35-year-old constable drove at up to 140mph while transporting a prisoner from Leeds to Darlington along the A1.

The prisoner promptly made a complaint about the officer's speed when the pair arrived at the custody suite at Darlington police station.

But while other highly skilled drivers caught speeding - including ex-Formula One world champion Nigel Mansell - faced prosecution and a driving ban, the Darlington officer escaped with a sanction following internal misconduct proceedings.

Durham's Police and Crime Commissioner last night criticised the decision not to prosecute the traffic officer.

Former police officer Ron Hogg said he could see no reason why the PC was not prosecuted - other than the allegation would not stand up in court.

Road safety charity Brake also spoke out about the driver's actions, saying police officers who break the law should face prosecution like members of the public.

Following The Northern Echo's revelations, Durham Police said that it was referring its handling of the case to the Independent Police Complaints Commission.

The IPCC will examine the investigation and decide if the force acted appropriately.

In a statement, Durham Police revealed that the complaint against the 35-year-old was made in December last year.

It said the officer was driving a marked BMW 330 diesel police car, which reached 140mph for “a short period of time”.

This incident happened when the officer was transporting a prisoner from Leeds to Darlington.

The force said the suspect was wanted on suspicion of theft and was being brought to Darlington police station for questioning.

This individual was then charged and remanded in custody.

The force said in a statement that after a “rigorous internal investigation”, the officer was moved permanently from roads policing duties, his police driving licence was suspended and he was subject to an action plan concerning risk management and decision making.

The officer was now performing a limited operational role which did not involve driving and would not return to full operational duties until it was deemed appropriate, the force said.

Asked to explain why the officer was not prosecuted, Superintendent Darren Ellis, head of the force’s professional standards department, said: “This action was deemed the most appropriate due to a number of key factors.

“The officer in question was an advanced and highly skilled police driver and there was no suggestion that the vehicle was driven dangerously at any time.

"The complainant has been made aware and is satisfied with the action taken. This error of judgement on behalf of the officer is as a result of a single incident and there is no evidence to suggest a pattern of behaviour, the officer’s conduct prior to the incident had been exemplary.”

Supt Ellis said he fully accepted that criminal proceedings could have been invoked.

However, he added: “After a full investigation it was felt that a more appropriate professional sanction in this instance would be the misconduct route due to the reasons I’ve outlined.

“Moving forward as a force we have taken the opportunity to reinforce the standards of driving expected from all officers and staff and are keen as an organisation to learn from this incident.

“We have also taken the decision to voluntarily refer this to the Independent Police Complaints Commission for their consideration”

Durham PCC Mr Hogg last night condemned the officer's actions, saying speeds of 140mph should not be reached, even in most pursuit circumstances.

Mr Hogg said had not seen his force's rationale for not prosecuting the officer, but added: “I can't see any reason why he shouldn't have been prosecuted other than it would be the prisoner's word against his.

“I don't think it would stand up in court with only the prisoner to verify what speed he was doing.”

The Northern Echo was also contacted by several serving police officers from the region who expressed concern at the decision not to prosecute the officer.

Assuming a driver had excellent reactions and was driving a car with good brakes the stopping distance, at 70 mph is 79 metres. But a vehicle travelling at 140mph needs 272 metres to come to a halt. Indeed, a car doing 140mph would still be travelling at 128mph when a car braking from  70 mph had stopped. If the road is wet, a car doing 140mph would need 532 metres to stop - nearly a third of a mile.

Joe Burns, spokesman at road safety charity Brake, said driving at very high speeds on public roads posed a “horrendous danger”.

He added: “Anyone caught driving in this reckless way should face appropriately stiff penalties, in light of the terrible harm they can cause, and to encourage respect for the law.

“We believe police drivers should be prosecuted if they have broken laws and endangered the public, and forces should be held to account in upholding strict safety standards.”