“I knew something was wrong as normally he would wake us up at 7.30am.

"I quickly rolled him over and started doing CPR, then tried mouth-to-mouth but rigor mortis had already set in and I couldn’t get his mouth open,” recalls Luke.

“It was then I started to fully realise what was happening but I didn’t want to believe it.

"The front of his body where he’d been lying was a bit warm, but the rest of him was cold.

“I remember feeling like it was painful for my skin to touch anything. It was as if my body was trying to detach itself from everything to make me think it wasn’t happening.

“That image of his face stayed in my head for months afterwards. Every time I’d try to sleep there it was.”

Georgia rang reception and an ambulance was called to their ­room in Sivota Resort, ­Thesprotia, but it was too late.

Dad and lad: Luke and Harvey (Image: Luke Ashworth)

Resort staff had been trying to help and even tried to fit a defibrillator but there were no signs of life.

A week later, Harvey was flown home, where he was given a postmortem before being buried the next month in a cemetery in Warsash, Portsmouth, near his home.

An inquest held last year gave a verdict of death by natural causes but couldn’t pinpoint a precise reason.

A ­pathologist could only point to the ­possibility of it being a “sudden unexpected death”, where medics can’t find the cause.

But this uncertainty has actually been a comfort to businessman Luke, 34.

“In some ways it’s almost nice not knowing,” he says. “If there had been ­something wrong that we’d missed, imagine the guilt that we’d feel as parents.

“But Harvey was a fit, young, healthy boy who did lots of sports including cricket, rugby, hockey and cross-country and wanted to be on the go all the time.”

The year before his death Harvey, described by all as a hugely popular, generous boy, cheered his dad on at the finishing line of the Bupa Great South Run and he was set to take part in the event’s junior section in 2011, but died three months before.

Luke is now preparing for this Sunday’s Great South Run in ­Portsmouth to raise money for the Naomi House Children’s Hospice, one of Harvey’s favourite charities.

But this time Luke will be flanked by Harvey’s Army – an incredible 64-strong group of friends, family and colleagues who are turning out to support him.