A doctor has been arrested after he helped a friend commit suicide.

Dr Michael Irwin paid £1,500 for Raymond Cutkelvin to have a lethal dose of the sleeping aid nembutal in the Swiss clinic Dignitas.

The 78-year-old claims he helped around 50 people to die during his 40-year career as a GP.

He said that many doctors help patients to die by supplying them with higher doses of diamorphine and sedatives.

Dr Irwin, of Cromwell Road, Hove, was arrested by police in London in July and is on bail until September 23.

Mr Cutkelvin, 58, from Hackney in London, was suffering from an inoperable tumour of the pancreas and requested to be taken to the Zurich clinic with his partner Alan Rees-Cutkelvin, 57.

Dr Irvin said: “I met Raymond and gave him £1,500, around a third of the total cost needed for him to got to Dignitas.

“I went with him and Alan and some family, we all had a last dinner together.

“The next morning we went to the clinic and arranged to have Raymond's favourite Mo Town music played so he could have his last dance with his niece to Diana Ross.

“It was surreal but beautiful.

“He sat down drank a sherry glass of nembutal and made a face because of the bitter taste.

“Within half an hour he was dead.”

The group travelled to Switzerland in February 2007, but were not arrested at the time.

However after the story was highlighted recently by the media Mr Rees-Cutkelvin was arrested in July.

Dr Irwin was so furious he called for police to arrest him too, which they did, a week later.

He said: “I gave financial support, moral support and advice. I consider myself equally involved.”

Dr Irwin said it is common for doctors to increase the painkillers and sedatives of patients who are dying.

He added that he could openly remember discussing the case of a Polish patient with terminal stomach cancer when he was a house physician at a North London hospital in 1956.

He would have been in his mid twenties at the time.

He said: “In those days you could openly discuss it with the ward sister and the consultants and we agreed to keep on doubling the morphine every day.”

During his career the Hove-based doctor said he helped patients in the United States and in South East Asia to die this way.

A survey of nearly 900 doctors by Professor Clive Seale from St Bartholomew's Hospital in London showed one in six people who are dying are given “terminal sedation” - meaning they are given so many painkillers and sedatives they die.

The shocking figures also revealed an estimated 1,000 people make a secret arrangement with their doctors to be given a lethal injection and 2000 are given one without their consent.

Dr Irwin said: “It's a total hypocrisy – if people have money they can pay to go abroad and have it done legally. The nembutal kills them over the space of half an hour.

“If they don't have money doctors give them a liberal amount of painkillers and sedatives and they die over the course of weeks.

“Most people in hospital die that way and there are no inquests into those kinds of deaths.”

Dr Irvin was struck off the medical register by the General Medical Council in 2005 after he admitted a willingness to supply his farmer friend Patrick Kneen with the necessary sleeping pills to help him die.

Mr Kneen never took the pills as he slipped into a coma before Dr Irwin could “treat” him but the GMC still found him guilty of serious professional misconduct and said his actions were irresponsible.

Dr Irwin said he has no regrets about what happened.

He said: “I'm just sorry for Patrick we got there too late.”

When he was arrested over Mr Cutkelvin's death he went to police with no lawyer and handed over his bank statement showing the direct transaction from his account to Dignitas.

Adding: “I have nothing to hide – I want to make this a big issue.”

A Metropolitan Police spokesman said: “Two men have been arrested in connection with the investigation, a 78-year-old man and a 57-year-old man.

“They were both arrested on suspicion of aiding a suicide and have been bailed to attend an East London police station on a date later in September.”