The son of former Falmouth town councillor Diana Merrett was found to have cocaine, heroin and anti-depressants in his system when he died in May.

It is not believed David Merrett, who had a history of drug abuse, intentionally took his own life, but he was found dead on his bed by a hospital transport worker who had brought Ms Merrett home from a stay in hospital. She had terminal lung cancer and died less than a month later.

An inquest in Truro heard that drug paraphernalia was found in Mr Merrett's room at the house he shared with his mother in Conway Road.

A postmortem showed that the cause of 49-year-old Mr Merrett's death was heroin and cocaine misuse. He was found to have a number drugs in his system including cocaine, morphine in the "lethal range" and an anti-depressant above the therapeutic range.

Dr Frances McCormick said Mr Merrett's death could have been from illicit heroin or cocaine use or a combination of both.

The inquest heard that Mr Merrett had lived with his mum "on and off" for most of his life. His gran, Dorothy May Scheppel, also shared the home, but she had died a month before and Ms Merrett was "very poorly."

On May 2 Ms Merrett was brought home after a stay in hospital by hospital transport staff, but they were unable to get into the house. "They could see him (Mr Merrett) lying on the bed," said DC Charlotte Robinson-Masters. "They managed to get in through the back door and found him on the bed, deceased.

"The back door was unlocked and there was no sign of forced entry, no sign of anything missing and no evidence anybody had been in. There was nothing suspicious at all.

"There was drugs paraphernalia - a bong was found, there was evidence he had been injecting drugs. There was a tobacco pouch containing cannabis and a little box with white crystals in a wrap and a sharps bin and replacement needles."

DC Robinson-Masters said she had spoken with Ms Merrett about his drug habit and was told he had started taking drugs as a teenager and had relapsed quite a few times. "I'm not sure his mum was aware how bad his drug habit was," said the officer.

"She said he was very upset after the death of his grandmother, but he told her he was going to stay around because he was going to look after her. She had no doubts that he was going to stay and look after her. There was nothing to suggest he was going to take his own life. I do not think this was intentional, I think it was a recreational accident by him."

Mr Merrett had suffered from mental ill health for several years and 12-months before his death had had a heart attack which led to him having a stent fitted and being put on medication. He had been very upset over the death of his gran and suffered from depression and anxiety.

Assistant coroner Barrie van den Berg ruled that Mr Merrett had suffered a drug related death, but said while it is not known conclusively what happened, it was most likely to have been an accident.

Ms Merrett had been a town councillor for the Smithick ward since 2007, but chose not to stand for re-election this year because of her failing health. She had been battling her cancer, but she died a week after her son's funeral and a days before her 69th birthday.

She had always stood by her son, even when he was jailed for 20 months in 2013 after assaulting a man. She believed he had given up the drugs, and in her last interview with the Packet had claimed his death was not drugs-related but he had died of natural causes.