A GRIEVING widow says she replays her last argument with her husband and wishes she had "said sorry" after he was found dead at his workplace.

Russell Walker, 42, was found by a colleague in a storage area at Diamond Light Source, the science facility in Harwell where he worked as an experimental hall coordinator, on January 5 this year.

Assistant coroner for Oxfordshire Rosamund Rhodes-Kemp yesterday said he died from carbon monoxide poisoning and recorded a suicide verdict at an inquest into Mr Walker's death.

In a written statement read at Oxford Coroner's Court yesterday, Helen Walker said the loving father of twin girls was "the last person I would expect to take his own life".

The inquest heard he used an electronic key fob to enter the premises on December 23, after an argument with his wife.

Mrs Walker, 41, from Abingdon, said: "I can't believe this has happened. In terms of our relationship I could not point to any major events... we argued but it was all trivial.

"It would reach boiling point and then we would clear the air and all would be well.

"I replay that last argument back in my head and wish I had said sorry."

Dr Eve Fryer, Mr Walker's GP, said in a statement that he had no history of depression.

However his wife said she had noticed "a slight change" in his behaviour in December after he had been promoted at Diamond Light Source.

Her statement added: "He became a little more distant. He had more responsibilities [at work] and the change coincided with the promotion."

On the day of the couple's argument, December 22, Mr Walker returned home from work after his last shift before the Christmas period.

Mrs Walker said they fell out over a bottle of wine that he had bought. In the morning he told her he had been "up all night" and told her he would go away until January 4 and when he came back he would sell their house, the inquest heard.

Mrs Walker reported her husband missing to the police on December 28, after learning he had not gone to his mother's home.

He was found by colleague Paul Symes, who suspected something was wrong after another work mate said Mr Walker's car had been parked outside Diamond Light Source over the Christmas period during a conversation about him being reported missing.

Assistant coroner Ms Rhodes-Kemp said: "He was a gas expert and would have understood the working of gas... the verdict I reach is suicide.

"It is a terrible thing for [his] girls to cope with and such a young age and you have my condolences."