Serving police officers in the West have criminal records for offences including assault, drink driving and fraud a Freedom of Information inquiry has revealed.

Wiltshire (no more than five), West Mercia (10) and Dorset police (nine) confirmed that between them more than 20 serving officers have criminal records including for public order offences, a domestic dispute and taking a vehicle without consent.

The Gloucestershire, Avon and Somerset and Gwent forces declined to state how many serving officers had criminal convictions under regulations in the Act that exempts investigation into a question if it is likely to cost too much money.

However all forces, apart from Wiltshire Constabulary, released information on the numbers of officers who have been sacked or forced to resign because of a criminal conviction since September 2003.

Dorset Police revealed that nine officers on its force have criminal records but that none of its officers has been dismissed.

Gloucestershire police confirmed that they had to dismiss one officer for breaking the law while Avon and Somerset confirmed three officers had been dismissed or were asked to resign.

Gwent police revealed that two officers had been dismissed in the five year period, while West Mercia police, who cover Hereford and Worcester, said one officer had been dismissed and two had been required to resign from the force due to criminal convictions.

Hereford's Liberal Democrat MP Paul Keetch said: "I am glad that West Mercia Police have been so open and honest about the situation and I am surprised that other police forces have not been so forthcoming.

"One would have thought the Home Office gave guidelines on this issue.

"I would presume that the Chief Constable would be aware of the circumstances and offences of any convicted officers and would ensure that these officers would not be involved in any operational activity in those areas or associated with anything relating to their crime."

Paul West, ACPO lead for the Professional Standards Working Group and Chief Constable West Mercia, said: "The police service expects good conduct and probity from its officers and staff at all times.

"Where wrongdoing is alleged, police officers are investigated and action taken as appropriate to each case.

"It should be remembered that there are just over 140,000 police officers in the country, the overwhelming majority of whom serve the public with dedication under sometimes difficult circumstances.

"In common with a large majority of British employees, police staff members are subject to the ACAS code of practice on disciplinary and grievance procedures, while police officers are subject to the Police and Misconduct Regulations set by Government.

"Where an officer has committed misconduct, which can include a criminal offence, a range of disciplinary actions can be taken by a police force, including a reprimand, fine, reduction in rank or dismissal.

"The force concerned will take action depending on a range of factors including the severity of the offence and its impact on an officer's ability to carry out their duties.