The badly-burnt body of a businessman was found sat at his kitchen table with his half-eaten dinner still in front of him, an inquest heard.
Police were confronted with the baffling mystery as they were called to investigate the death of 68-year-old David Dennis.
The inquest on Friday heard a Home Office pathologist found Mr Dennis may have died before the fire happened – and that he had a potentially fatal level of the veterinary tranquiliser Ketamine in his body.
Detectives then unearthed allegations that both Mr Dennis’ sons had grudges against him, the court heard.
One had allegedly tried to run him over and the other had threatened to kill him, GloucesterLive reported.
Police also learnt that the day before his death Mr Dennis had been in an angry dispute over money with a workman who was cutting trees on his land.
Officers also looked into Mr Dennis’ partner Judy Barrington – who had served him with his dinner one night and then found him dead the next morning – and stood to gain from his will when he died.
The investigation showed no evidence could be found to suggest any of them had been involved in the death.
Gloucestershire coroner Katie Skerrett ruled there was no foul play and the death was either natural or drug-related.
She could not be sure from the medical evidence, she said, whether the Ketamine killed Mr Dennis or he died from a ‘medical episode’ – a heart seizure – as the fire was breaking out in his kitchen on Sunday, July 23 last year.
Mr Dennis, a former plant hire operator, from Castle Tump in Newent was found dead still sitting in the place where Ms Barrington, who lived in a converted barn next door, had served him an evening meal, the inquest heard.
Fire investigator Richard Lockyer told the inquest he believed Mr Dennis had a pile of glossy magazines on the table but had picked them up and turned to put them on the hob behind him to make more space.
“I don’t believe he knew the hob was on,” Mr Lockyer said.
“I think he has then had a medical episode and the heat has ignited the brochures, which went onto the floor.
“I believe he was already incapacitated at that point and had possibly even passed away before the fire really started.”
Enquiries revealed Mr Dennis had been involved in a ‘disagreement’ over £50 with a workman the previous day, the officer said.
That had reportedly caused him ‘some anxiety and distress.’
Sgt Marcus Forbes-George of Gloucestershire police said Mr Dennis had two estranged sons – one of whom had allegedly threatened to shoot him while the other had supposedly tried to run him over.
Home Office pathologist Dr Andrew Davison said Mr Dennis had burns over 50 percent of his body.
There was no carbon in his upper airways so he either died before the fire started or almost immediately after it began.
He had a very large heart and known high blood pressure so although there was no sign of a coronary attack he may have suffered an abnormal rhythm which caused death, said the doctor.
He told the inquest subsequent tests revealed Mr Dennis had 20mls per litre of Ketamine in his blood.
This was a very high level which could have caused death.
He also had Ketamine in his stomach, indicating he had ingested the drug rather than injected or snorted it.
Analysis of his hair revealed that he had been using Ketamine for at least six months.
Ecstasy and codeine traces were also in the hair.
The doctor said that, on balance, he believed Mr Dennis had died before the fire began.
In a statement, Ms Barrington spoke of the ‘ongoing issues’ between Mr Dennis and his two sons and said there had been an incident when one of them had driven at his father in the yard.
A few days before Mr Dennis’ death, she said, he went to see his GP in Mitcheldean with chest pains and was told to go straight to A&E.
She took him there and he had an ECG but then left before other tests could be carried out.
He was on medication including beta blockers and Zopiclone and he had been illicitly obtaining more Zopiclone tablets than he was prescribed, she said.
She told how he suffered from depression, drank heavily, and had spoken about taking his life if there was a way of doing it painlessly.
He had also been upset lately about losing his plant operator’s licence.
Earlier last year police had taken away the loaded gun he kept in his bedroom because she was so concerned that she called them about it, she stated.
Det Sgt Jonathan Williams told the inquest that the scene which confronted police when they first arrived was ‘not readily explainable.’
He said the allegations about the sons and the workman were fully investigated and no evidence could be found to suggest that any of them had been involved in the death.
The source of the Ketamine had not been found despite their enquiries, he added.
Asked if there could be a financial motive for Mr Dennis’ death, the officer said “We were aware that in the event of his death Ms Barrington would stand to inherit a sizeable sum but the main bulk of his estate was going to a charity.
“There was no apparent reason for any ill will towards him from her.”
Nothing appeared to have been stolen from the farmhouse, he added.
The officer concluded “In my opinion, Mr Dennis died from a medical episode either caused by his physical health or the use of drugs and he passed away and the fire was an accident that was a strange occurrence.”
Closing the inquest the coroner said she found on the balance of probabilities that he died from either natural causes or Ketamine.
“In all probability this was an accidental fire after the ‘main event,'” she said.
“This was a medical episode caused by his health and/or drugs. If any evidence comes to light as to the source of the drug perhaps other lines of enquiry can be opened up.”