Arthur Bond, 79, was attempting to light a Calor gas fire at his home at Glebe Farm, in the village of Great Brington, on January 26 when a sudden flash of flames is believed to have set his trousers alight.

Speaking at the inquest at Northampton General Hospital, forensics expert Roderick Stewart said the pensioner had walked into the kitchen in an attempt to "put himself out" but was unable to stop the fire from spreading.

The farmer suffered severe burns to the legs and the rest of his body after he was overwhelmed by the fire.

Three fire crews from Long Buckby and Daventry dealt with the blaze, which also caused severe damage to the farmhouse kitchen.

Mr Bond lived at the farmhouse with his wife, Betty, and the couple had six children.

The inquest heard from his son, Stephen, who said the gas fire was sometimes hard to light but that his father had a knack of doing it.

He said his father suffered from arthritis but did not want to move and would not be forced into leaving the Great Brington farm.

Deputy County Coroner Rodney Haig said: "The portable gas fire appears to be the only source of the fire.

"Mr Stewart believes there may have been a build-up of gas and, when ignited, it caused a flash, which sadly caught Mr Bond's clothing.

"The most reasonable explanation is that he then walked into the kitchen to douse the flames, but became overcome and this caused the fire to spread to the rest of the kitchen."

A verdict of accidental death was recorded.