A father-of-three held his wife hostage before apparently shooting himself dead - just days before they were set to appear on TV show DIY SOS.
Jenny Walters, 41, who suffers from a rare neurological disorder, contacted emergency services on Sunday saying she was being held prisoner by her husband Mark, 48, at their home in Watford.
When police officers arrived at the scene, Mr Walters, a gardener, was found dead inside the house.
The couple were due to feature on the BBC1 home renovation show presented by Nick Knowles on Bank Holiday Monday.
A Hertfordshire Constabulary spokeswoman said officers had been warned Mr Walters had a firearm but the incident is not being treated as suspicious.
She said: "Police attended a property in Bushey Mill Lane in Watford at around 7.30am on Sunday May 23. When officers entered the property they found a man in his late forties had passed away.
"Officers are investigating the circumstances of the death, however at this stage it is not being treated as suspicious. Officers were attending the property to investigate an allegation of false imprisonment which is reported to have taken place earlier that morning."
Police were waiting for the results of a post-mortem examination, she added.
A spokeswoman for the BBC confirmed the couple had been filmed for the TV makeover programme. Work carried out on their semi-detached home was believed to have included a new kitchen. Film teams were understood to have visited the family last June after building work to their home ground to a halt when Mrs Walters fell ill.
According to a newspaper, Mr Walters said of the filming: "It has taken my mind off what happened. They have almost let off a pressure valve in me, because I think if I had sat back and thought about what was going on, I would have just lost it."