A pest controller killed himself by releasing deadly cyanide gas into his van, an inquest jury decided.

Paul Wellstood, 43, a married father-of-two of Berrycroft, Abingdon, was found slumped in his van at Great Rollright, near Chipping Norton, on August 13 last year.

A Health and Safety Executive investigation established that cymag gas being carried in his van escaped and reacted with moisture to produce lethal hydrogen cyanide.

Paul WellstoodA post-mortem examination showed the amount of cyanide in Mr Wellstood's blood was 5607mg per litre - more than 50 times the lethal amount.

But inquiries failed to establish why he was carrying cyanide, or why normal high-security measures, including transporting the chemical in a sealed metal ammunition box, were not carried out.

The inquest in Oxford heard yesterday that Mr Wellstood, a partner in Abingdon-based Household Pest Services, and his wife Yvonne were having marital problems.

Mr Wellstood's sister Linda Murphy, of Maple Avenue, Kidlington, also told the inquest that he had taken an overdose in 1981 because of problems with a girlfriend, and had been involved in an accident "of dubious cause" in 1992.

She said: "When I asked him if it was an accident he didn't say anything, he just cried.

"Knowing him, if it was an accident he would have told me to stop being so stupid -- so I assumed it wasn't an accident."

Mr Wellstood's business partner of eight years, Peter Booth, of Windrush Road, Berinsfield, told the inquest both he and Mr Wellstood carried an antidote to cyanide in their vehicles, but rarely used the chemical itself.

He said: "I was very surprised Paul had cymag in his vehicle, I would not have expected him to be carrying it routinely.

"The rule was nobody ever used it on their own.

"It was largely used for control of rabbits over the winter months, not summer months."

Health and Safety officer Anthony Mitchell said the reaction had been caused by a plastic container of insecticide in the back of the van leaking into a heap of cymag powder which had spilled from a tin.

Pc Phil Newbury, of Thames Valley Police, said the van had been 'slowly driven up and parked', which made it unlikely the gas had been released accidentally while the vehicle was in motion.

The inquest jury returned a verdict that Mr Wellstood took his own life by chemical poisoning.