A dad-of-two with an agonising back injury was found dead in bed after unintentionally overdosing on painkillers, an inquest has heard.

Oliver Griggs, 31, was discovered unresponsive by his heartbroken partner at their home in Birchington-on-Sea.

A post-mortem examination would later reveal he had high levels of morphine, codeine and tramadol in his system at the time of his death.

The inquest was told he had been prescribed the strong painkillers as he was suffering with a slipped herniated disc in his back.

Coroner Sarah Clarke said: “I think taking the medication had unintended consequences. I think he was trying to get on top of the pain.

“It just so happened on this night, it was too much.

“No one other than Oli himself is aware of the quantities he was ingesting.”

The court heard Mr Griggs – known as Oli to family and friends – took the course of medication while awaiting surgery and struggling to work.

He had spent the last year of his life in and out of medical settings because of the debilitating injury.

On one occasion, he became so overwhelmed with pain he was unable to get out of the bath.

He and his partner of almost nine years, Jodie Clay, were planning to marry and visit Disneyland with their children at the time of his death in November – facts that supported the coroner’s conclusion that Mr Griggs had not intended to take his own life.

The coroner gave the cause of his death as a fatal opioid overdose, ruling it to be misadventure after toxicology reports found all three medications to be at potentially fatal levels.

Obesity and cardiomegaly – an enlarged heart – were listed as secondary factors.

Mr Griggs’ family raised concerns with the coroner over the way his pain management was handled and a lack of close monitoring regarding his medication.

The hearing was told Mr Griggs' was aware of the addictive nature of the drugs, and that discussions over dependency had been had with GPs and Miss Clay.

Doctors had offered advice on using the medication and refused to increase his morphine dose.

Another appointment had been scheduled for the day after Mr Griggs died.

The coroner said: “Concerns over the medication are not concerns I’ve taken lightly.

“The GP clearly became aware [Oli] was taking more than he should have of his medication. All of those medications together lead to respiratory depression.”

Miss Clay previously paid tribute to the “hard-working” dad, recalling the shock of discovering him dead.

“I don’t think I’ll ever get past that,” said the 29-year-old.

“It’s like my whole life has gone on hold because I’ve got to be mum and dad and everything in between.

“I just want to be able to continue to give the kids the life they had with Oli.”

The youngest of four siblings, Mr Griggs was passionate about motorcycles and was a key figure in the lives of his sons, Vinnie and Harry.

A friend of Miss Clay’s set up a fundraiser to help cover the funeral costs and help the family through Christmas, with more than 150 people donating a combined £3,000.

His family said: “Oliver absolutely adored his family and his boys.

“All his friends will speak of how happy, laid back and easy-going he was.

“Everyone who knew him adored him; he was a joker and an absolute one-of-a-kind top guy.

“He would do anything for anyone and he brought smiles and belly laughs everywhere he went.

“Oliver lived his life to the full and he truly touched the lives of everyone he crossed paths with. He’s left a huge hole in so many people’s worlds.”