The jury in the murder trial of Ian Stewart, who stands accused of murdering his wife Diane at their home in Bassingbourn in 2010, have retired to consider their verdict.

Diane was originally thought to have died of SUDEP - the sudden, unexpected death of someone with epilepsy - in the garden of her marital home in 2010.

Stewart told the court that he found his wife collapsed in the garden when he returned from the supermarket.

He said he tried to revive her, attempted to contact neighbours who were a doctor and nurse, tried again to revive his wife, and then called 999.

However, police launched an investigation into Diane's death after Ian Stewart - from Letchworth - was found guilty in 2017 of murdering his fiancée, Royston author Helen Bailey the year before, and dumping her body and her dog Boris in a cesspit beneath the home they shared.

The latest trial began at Huntingdon Crown Court on January 17 and has heard evidence from several parties - including Stewart and Diane's sons, the paramedic who was first on the scene, Mrs Stewart's sister, Wendy Bellamy-Lee, and neuropathologists.

Diane's body was cremated but Prof Al-Sarraj was able to examine the brain of the deceased after she agreed for it to be donated to medical science.

Prosecutor Stuart Trimmer said analysis of her brain tissue indicated her death was "most likely caused by a prolonged restriction to her breathing from an outside source".

In court Prof Al-Sarraj said he observed "changes in the brain... consistent with early ischemia". He defined ischemia as "damage to the cells due to lack of oxygen and blood supply".

A second expert witness, consultant neuropathologist Dr Kieren Allinson, said there was "no positive evidence of a recent seizure", and that absence of evidence of a seizure "doesn't make it unlikely that SUDEP occurred".

Stewart denies the murder of his wife.