A former detective is suing Thames Valley Police for alleged negligence, claiming he was injured while being trained in restraint techniques.

William Crickett, 45, is seeking damages for a shoulder injury which he says was inflicted by a police instructor on a course at Upper Heyford.

He claims an instructor demonstrating the "ground pin" method of restraining and quick-cuffing a suspect caused the injury by kneeling on his shoulder and moving his arm outside its normal arc while asking him if he was able to move.

Mr Crickett left the police on medical grounds in 2000.

In a trial at Oxford County Court this week, his barrister, Robert Weir, argued that Thames Valley Police had breached the duty of care it owed him as an employee and should be liable to pay damages for negligence.

Simon Wheatley, defending the police, said the instructor was experienced and had demonstrated the technique on thousands of personnel in the past without any prob- lems."It is one of the tools of the trade," he said.

He added it was necessary to expose staff to a degree of risk in training to make it reasonably true to life.

Judge Charles Harris said he would give his judgement early next week.