A car salesman who caused the death of a doctor while he was showing off a high-performance car was jailed for nine months yesterday.

David Goodwin lost control of the Subaru Impreza Turbo during a test drive as he hit speeds of up to 90mph on a country road.

Dr David McBeath, who had been interested in buying the 140mph car, was killed when it hit a BMW.

Goodwin, 36, from Glendoick, Perthshire, previously admitted causing death by dangerous driving on the outskirts of Perth on May 18 this year.

Sheriff Fiona Reith said she had no option but to jail him as a warning to other motorists. She said: ''This really must have been a horrifying experience with terrible consequences for Dr McBeath's wife and family.''

Outside court, the GP and part-time police surgeon's father, Mr Malcolm McBeath, from Kirriemuir, said he was angry and bitter about his son's death.

He said: ''No sentence, however severe, will make up for the loss of our son and we cannot help feeling angry and bitter about the circumstances of his death.

''This is a waste of a young life. His work as a GP was, by all accounts, well respected by his patients and colleagues and he could have benefited so many people in his lifetime.''

Dr McBeath, 29, from Kinross, had been married to his wife, Janet, for nearly three years and worked at Loch Leven health centre. He had asked to test drive the Subaru from Anderson Cars in Perth.

Perth Sheriff Court was told Goodwin had been a salesman with the company for only a few months before the accident. He had taken Dr McBeath and his colleague Dr Jonathan Blake, from Stonehaven, out in the car.

A short distance from the garage he turned into a quiet country road and put his foot down.

He lost control and crashed into an oncoming car. The Subaru was thrown into the air and landed in a field. Dr McBeath, who had been the front-seat passenger, was killed outright.

Defence agent John MacEachern said his client, now a lorry driver, had suffered post traumatic amnesia and could not remember the crash.

Mr MacEachern told the court: ''His driving has been extensive in nature - in excess of one million miles - and this tragic, horrendous and unexplained piece of driving is the first occasion in which he has found himself before the court.''

He said the accident was an isolated piece of driving from a man who had until then lived a blameless life.

The court had heard earlier how Dr Blake had become frightened at the speed Goodwin was doing in the seconds before the crash.

Accident investigators said the Subaru was travelling at 81mph when it struck Mr James Gray's BMW, although it could have been 10% higher.

Goodwin, a former prison officer involved in riots at Saughton jail in Edinburgh, broke his leg and ribs.

The court heard he had been dismissed from the company after the accident and had now lost his job as an HGV driver.

Goodwin had previously had a letter of apology to Dr McBeath's family read in court.

He said: ''I simply do not have the words to convey how I feel about this tragedy. Many of my colleagues were patients of Dr McBeath.

''Everyone said he was a man from a wonderful, loving family, as I am. I know these words are futile and I know that neither I nor his family will ever get over this tragedy.

''I have to bear the consequences of it for the rest of my life.''

Sheriff Reith said she would have jailed him for longer but, as a former prison officer, he would face a particularly hard time in jail and would be placed on constant protection.