Ian Stewart has been sentenced to a whole life order for the “horrifying and terrifying” murder of his first wife, Diane, in 2010.

He was previously sentenced to life imprisonment with a minimum of 34 years for the murder of Helen Bailey in 2017.

Stewart, 61, was jailed for life in 2017 for drugging and killing his fiancée and her dog in a plot to get his hands on her £4 million fortune. 

He dumped her body in a cesspit below their home in Royston, Herts, in April 2016 and she lay undiscovered for three months as Stewart elaborately staged her disappearance. 

The couple had met on a forum for the widowed, where Stewart had been hunting for women to target after the death of his wife, Diane, in the garden of the family home in 2010. 

A coroner gave Ms Stewart’s cause of death as “sudden expected death in epilepsy”, but detectives re-examined the case after Stewart was convicted of Ms Bailey’s murder. 

It was “a stroke of fortune”, as prosecutors described it, that allowed police to finally pin the murder of Ms Stewart on her husband.

Prosecutor Stuart Trimmer QC said her death was “most likely caused by a prolonged restriction to her breathing from an outside source”, such as smothering or a neck hold.

The court heard that full toxicology was not carried out as part of the 2010 routine post-mortem examination, and nor was a neck dissection.

Stewart had taken care to ensure his first wife was cremated, destroying with it, he hoped, any evidence of his terrible crime – save for one crucial detail. 

Ms Stewart’s brain was donated to medical science and, remarkably, it meant there were still tissue samples available for a team of experts to examine around a decade later. 

The preserved parts of Ms Stewart’s brain held the true answer to her fate.