NHS Tayside has claimed rates of violence and restraint in its mental health services are not excessive compared with other health boards, after an internal report claimed patients in Dundee had been pinned to the floor for too long and in a dangerous position.

The report examined practices in the city's Carseview Centre, which was the subject of a BBC Scotland expose in July last year. The documentary included allegations by patients of bullying by staff, use of illegal drugs and patients being inappropriately restrained.

A report commissioned by the board of NHS Tayside in response has not been published but was leaked to the BBC which said it revealed that untrained staff at the hospital for patients with mental illnesses had used risky restraint methods , including pinning people face down on the floor. This happened frequently and sometimes for long periods. The report says this kind of physical restraint should only be used once other approaches have failed as it it is one of the most dangerous techniques that staff can deploy.

The acting medical director for NHS Tayside, Professor Peter Stonebridge said the reports findings were being acted on and added that there would be an "unrelenting focus" on improving mental health services.

However he added: "We report our rates of violence and restraint to the Scottish Patient Safety Programme for Mental Health and it is clear that our median rates of violence and restraint do not make us an outlier with other mental health services in Scotland."

He said a steering group was specifically charged with making sure patients with mental health problems received the "least restrictive" care possible. "people have told us about the impact restraint has on their mental wellbeing and we will ensure that their stories drive forward the reductions we are determined to achieve," he said.

"last year the board of NHS Tayside said it would be working closely with mental health services at Carseview and it would act where changes were necessary.

"We are acting on the recommendations in the internal assessment and are determined to make a difference and support our dedicated staff to deliver the best possible mental health services across Tayside."

The report makes 11 recommendations for change. These include developing work with Police Scotland to block the use of illegal substances on wards, and work with the public health services and the Scottish Fire and Rescue Service to reduce unwanted fire alarms and encourage patients to quit smoking.

The report says policies and training should be reviewed to focus on "least restrictive practise" and engage with staff to improve services. Staffing should also be addressed with more effective rotas, productivity and training.

The report also says concerns about leadership could be addressed by staff using whistleblowing policies.

NHS Tayside said these recommendations had been shared with staff and there were currently 50 staff participating in "improvement projects".

The internal report is believed to have said one whistleblower has already accused the centre of "Very serious concerns over leadership, safety and malpractice."

Meanwhile the report's authors looked at a sample of 40 cases and found more than half of the patients it surveyed had been restrained face down, on the floor, for more than half an hour. The BBC claims one restraint was continued for one hour and 45 minutes.

David Fong, who spent a month in the centre after being diagnosed with psychosis six years ago, told the BBC he had often witnessed staff using violent methods of restraint during his time there. "I personally was physically assaulted with the application of intense pain through twisting of arms, wrists and fingers, or a member of staff's knee being dug into my back, had my face rubbed into the floor causing loss of skin from my face, and had verbal abuse screamed at me during restraint," he said. "I could not have been the only patient that these tactics were being used upon."

An NHS spokeswoman said: "Patients, carers and staff would al be asked to help inform changes and improvements to services.

A Mental Welfare Commission spokesperson said the watchdog would not comment on a leaked document, but added: "

“ We ...will clearly state that the misuse of restraint is unacceptable. We support the work being undertaken by the health board and staff to address the concerns raised by the BBC and by patients in relation to restraint. We also await the results of the independent inquiry commissioned by the health board.

“ Being restrained can be frightening, potentially dangerous and undignified. It should be seen as a last resort intervention. It should be used only where there is absolutely no alternative that would reduce an identified, specific risk to the person concerned to an acceptable level."