Adrian Prout, 49, then wrapped his wife Kate’s body in a curtain and placed it in the back of his Land Rover and drove to a pub.
He later drove into woodland on his farm at Redmarley, Gloucestershire and buried her body in a pheasant pen.
Prout kept up the pretence his wife was missing and despite being convicted of her murder two years ago continued to protest his innocence while family and friends of Mrs Prout, 55, pleaded with him to reveal where he had hidden her body.
In a dramatic twist last summer, however, he failed a lie detector test.
And in November he finally confessed to his then fiancée Debbie Garlick who told police. Days later he took detectives to the spot in Cobhill Woods where he had buried the retired teacher.
Mrs Prout’s remains were found wrapped in a curtain and plastic sheeting, the inquest at Gloucestershire Coroner’s Court heard yesterday.
A post-mortem examination failed to establish her cause of death but further tests revealed injuries to her neck consistent with strangulation.
A coroner recorded a verdict of unlawful killing during a brief hearing.
The court heard that during the lie detector test on August 16 Prout was asked the question: ‘Did you murder Kate Prout?’.
He denied it but the test showed he was lying.
The day after confessing to Ms Garlick, police interviewed Prout and he admitted he and his wife had an argument at about 5.30pm on November 5, 2007.
Prout said he was inside the shooting lodge preparing for a pheasant shoot the next day when Mrs Prout joined him, threatening to “embarrass him” in front of their clients.
He told officers he just “lost his temper and snapped” and strangled his wife before going to the pub to “maintain an air of normality”.
Detective Inspector Steve Bean said: “He said he had snapped and he had thrust his hand to her neck and squeezed as hard as he could for about 10 or 15 seconds, which had forced her backwards onto the floor. She had not struggled at any point but when she stopped moving he realised he had in fact killed her.”
Det Insp Bean said Prout went inside his house and had a whisky before returning to the lodge and wrapping her body in a curtain and white plastic sheet. He put it into the back of a Land Rover and drove to the pub.
Following his confession, police took him from prison to his former farm, which has since been sold, where he identified an area of 5 metres by 15 metres where Mrs Prout was buried. After several days of searching by specialists her remains were recovered.
The coroner said: “The confession given four years after this horrific event is clear and unequivocal.”