Detectives from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit arrested the man, of Bedford, on Tuesday following the re-examination of the death of 47-year-old Diane Stewart. The 57-year-old has since been released under investigation. Ms Stewart whose former husband Ian Stewart is currently serving a life sentence in prison for killing his fiancée, Royston author Helen Bailey, in 2016 was found dead at her home in Bassingbourn on June 25, 2010. At the time Ms Stewarts death was found to have been of natural causes, after an epileptic fit. Following her death, Ian Stewart joined a forum for widows and widowers, and the forums Facebook group, which Ms Bailey had also joined after her husband John Sinfield died in Barbados in 2011. During the 2017 murder trial, where Stewart was sentenced to a minimum of 34 years in prison after killing 52-year-old Ms Bailey and dumping her in a cesspit beneath their home alongside her beloved dog Boris, he said Ms Bailey had messaged first and they eventually got together through their shared grief. In the wake of Stewarts sentencing on February 23, 2017, DCI Jerome Kent who led the murder investigation said that he would also be heading a probe into the death of Stewarts former wife Diane, who he had two sons with.