A man who was found dead, naked from the waist down and slumped on his sofa in his flat in Chesham, had committed suicide by ingesting e-cigarette liquid, an inquest heard today.

Jonathan Keen, 46, was found in his bottom floor flat in Eskdale Avenue on Thursday, September 24 this year.

The court heard how Mr Keen, a broadcast engineer, would regularly mix his own concentrations of nicotine to use in e-cigarettes – battery-powered vaporisers that simulate the feeling of smoking without burning tobacco.

DC Edward Blackburn, of Force CID based at Aylesbury police station, said Mr Keen’s girlfriend Vanessa had grown concerned when she had not heard from him since the day before and visited his flat on Thursday evening.

When he did not answer the door, she saw through a gap in his curtains that he was slumped on the sofa and called his landlady and the ambulance service, who then called the police.

When DC Blackburn arrived at the scene, he said Mr Keen had ‘clear liquid’ around his nose.

He said: “On the coffee table in front of him was a bottle of e-cigarette fluid and various empty cider cans were found in the kitchen.”

He also told the court how Mr Keen had sent a text to his cousin the day before he was found dead, with a picture of the back of an e-cigarette fluid bottle ‘showing the toxic warning sign.’

Apparent suicide notes were also found on the kitchen table and in the bin.

Coroner Richard Hulett said: “We have a note here that talks about being sorry and talking about who gets what. That is the sort of thing people write at a very late stage.

“Appearances are to me that for whatever reason, his frame of mind that night became very negative.”

Dr Peter Johnson, the pathologist at Wycombe Hospital who carried out the post-mortem, ruled that the cause of death was nicotine and alcohol toxicity.

He said that Mr Keen was a ‘functioning alcoholic’ and that toxicology reports showed he had ‘significant’ levels of nicotine and ethanol in his blood that had been ingested over a ‘short space of time.’

Mr Hulett recorded a conclusion of suicide and said he had not come across a case like this in Bucks before.

He said: “He was intoxicated and seemed to be cross about things. He has ingested this nicotine liquid and it is probably not widely known that nicotine is a serious poison.

“Looking at his notes and the toxicology, he got into a frame of mind where he decided to do this. What he was feeling was quite negative.

“Nowadays, nicotine is available in liquid form for e-cigarettes and you can import the stuff in a stronger form. This is the first time I have heard of someone dying directly from this in Buckinghamshire.”

Mr Keen’s brother, Adam, who described his sibling as 'loving and extremely considerate', is now trying to raise awareness of the danger of e-cigarettes, and intends to lobby his MP to try and get e-cigarettes regulated by law.  

While there has been some contention over the lethal dose of nicotine, Mr Keen said studies have shown that figures for a fatal dose, oral or IV, have been stated to be 'anywhere from 30mg to 60mg.'

He said: “E-cigarettes are positioned as being very safe and a positive way of being able to reduce dependence on nicotine and it is not true.

“It is my belief that it should treated be as drugs. There should be clear warnings on them about how strong they are and how dangerous they are.

“Any vape shop can make their own solutions and I want that to stop. I think it should be legislated.

“What my brother did was very unusual. He used to manufacture his own liquids himself. He was clever so he knew how toxic it was. The fact my brother should use this way shows it is a deadly poison and needs to be controlled.”