Mrs Thomas was strangled by her husband in July 2008 while they were on holiday in Aberporth, West Wales. While parked in their camper van Mr Thomas dreamt that one of a group of “boy racers” who had disturbed them earlier had broken into the van and he fought with the intruder. When he came round he realised that he had killed his wife of 40 years.

The court was told that Mr Thomas had suffered from a variety of sleep disorders for most of his life and had a history of sleepwalking.

He had stopped taking medication for depression and Parkinson’s disease because it made him impotent, an omission that also affected his mental state.

The expert witnesses were briefed not to go into too much detail about the condition that affected Mr Thomas for fear of “copycat” killings.