Dr Iain Kerr, from Glasgow, was yesterday told his registration to practise medicine would be temporarily withdrawn by a panel of the General Medical Council, who said it was "necessary to send a message to the medical profession that this behaviour is unacceptable".

Dr Kerr, who used to be a member of the Voluntary Euthanasia Society of Scotland, gave the retired businesswoman known as Patient A sodium amytal tablets in 1998 to allow her to kill herself.

Later, in 2005, he visited her after she took an overdose of Temazepam in a failed suicide bid and did not admit her to hospital. He then prescribed her more Temazepam and she died of intoxification from this and other drugs within a fortnight.

John Donnelly, chairman of the panel, said: "The panel is of the opinion that you allowed your views in respect of physician-assisted suicide to influence your treatment of Patient A. You made a serious misjudgment and embarked upon a potentially criminal act."

Dr Kerr's failure to make a record of why he had prescribed sodium amytal to a small number of other patients was also a factor in the panel's decision.

In reaching a judgment Mr Donnelly said the panel took into account the broad range of testimonies from colleagues, patients and their families showing Dr Kerr is held in high regard.

The views of Dr Harry Burns, chief medical officer who reviewed Dr Kerr's practices when he was director of public health for NHS Greater Glasgow, were also considered.

Dr Burns and a colleague undertook an investigation in 2004 because Dr Kerr had admitted prescribing sodium amytal so a patient could take their life, in a staff appraisal.

Dr Burns said: "Dr Wallace and I are convinced that we are not dealing with a doctor who is systematically involved in supporting assisted suicide. He seems motivated by the principles of helping his patients."

The panel said in view of the mitigating factors a suspension of six months was sufficient to "maintain public confidence in the profession, protect the public and uphold proper standards of professional conduct and behaviour".

On Wednesday, Michael Mylonas, counsel for Dr Kerr, said if a suspension was imposed the GP would be obliged to pay for locum cover if he wanted to carry on practising at the end of the period. He told the panel Dr Kerr, who is 61 and works at Williamwood Medical Centre in Clarkston, would probably tell the NHS he could not maintain that. "That will be an end of this doctor's practise," he added.

After the panel announced their determination yesterday, Dr Kerr gave a short statement outside the GMC offices in Manchester.

He said: "The Fitness to Practise Panel has carefully considered all the facts and the evidence and I am grateful to them for taking into account the exceptional and unusual circumstances advanced on my behalf.

"I am particularly grateful to family, friends, colleagues and patients for their continuing support and in particular I would like to single out for praise the staff of the Medical and Dental Defence Union of Scotland.

"The only other person I really want to thank in my name is my wife who has been a great support to me during this period."