A man who killed his wife and buried her under the floorboards of their home could have got away with murder but for love letters to his mistress revealing his plan, a new TV documentary has revealed.
Harry Jarvis hid his lover Rita Heyster in his garden shed before murdering wife Carol and leaving her decaying body in the cellar in 2009.
When they reported her missing, he told his children she had travelled to Dundee, where their daughter was a student, or gone into respite care.
Jus-Rol pastry heiress Heyster, who inherited and squandered a £2.5 million fortune, helped him to conceal the body at his home in Bathgate, West Lothian.
Investigators who worked on the case have now revealed there were serious doubts about whether the case against Jarvis was strong enough due to a lack of evidence.
The cause of 47-year-old Carol’s death could not be determined due to decomposition and Jarvis claimed she died during a fit.
He said he buried her at home to remain close to her.
In the Crime+Investigation channel documentary Killer Britain, presented by Dermot Murnaghan, the lead police officer and prosecution lawyer said the discovery of the letters was crucial to convicting Jarvis of murder.
The notes revealed Jarvis planned to move Heyster into his home after he had killed his wife and in one he wrote: “Drugs are doing job.
“Just took longer than I thought but going fast now. See you in Paradise soon.”
Former Detective Chief Inspector Phil Gachagan, who led the murder probe, said: “He said he had placed her beneath the floorboards and occasionally would go down and lie beside her and speak to her because he found it very difficult to be without her.
“Obviously in my mind that was complete fantasy.
“I had meetings with the Crown solicitors and there was a real worry that there wasn’t enough evidence to even take the case to court.
“The one thing that really helped with the investigation was letters that Jarvis had written to Rita which indicated he was drugging Carol and was planning on killing her.”
Garry Allan QC, who led the prosecution case, said: “The notes suggested Carol’s death was imminent and Harry and Rita could move on to a life in ‘paradise’.
“It was a very dramatic picture which I was able to present to the jury and show this was not an unfortunate death which had resulted in panicked decisions being made.”
Mum-of-four Carol, who had several medical problems, was reported missing by her children.
They did not believe their father’s account she had taken a trip to Dundee or gone into respite care.
Former bus driver Jarvis was jailed for a minimum of 15 years in 2011 and died of heart failure aged 67 in 2017 while serving his sentence at Addiewell prison.
Heyster, from Coldstream in the Borders, inherited a £2.5million fortune from her adopted father, Jus-Rol founder Tommy Forsyth.
But she fell on hard times and blew the cash before starting an affair with Jarvis.
She was jailed for four-and-a-half years for helping to conceal Carol’s body.
In 2015, the pair planned to marry behind bars but just a month later Heyster called off the wedding.
RKiller Britain with Dermot Murnaghan will be shown on Crime+Investigation at 9pm on June 4.