A "wicked" and "manipulative" man who murdered popular children's author Helen Bailey and dumped her body in a cesspit at their home has been jailed for life as police confirmed they will examine if his first wife was also killed.

Ian Stewart, 54, was found guilty of murdering his fiancé Bailey as part of an attempt to get his hands on her multi-million pound fortune after spending months drugging her with sleeping pills to eventually make it easier to suffocate her with a pillow.

Bailey's body was eventually recovered from a cesspit underneath their home in Royston, Hertfordshire in July 2016, three months after she was reported missing. It is believed Stewart murdered the author of the Electra Brown novels on 11 April before dumping the body in the grounds under their garage along with her pet dog.

Stewart was found guilty of her murder following a six-week trial at St Albans Court and has now been jailed for life with a minimum of 34 years. He refused to attend the court for the sentencing hearing and instead appeared via videolink.

Police have also confirmed that they will re-examining the "sudden, unexpected" death of Stewart's first wife, Diane, who died from what is believed to be an epileptic fit at their home in 2010. Officers said they isn't any clear indication that his first wife may have murdered but will look at the evidence once again.

Bailey and Stewart met through an online group for people who had lost their spouses. Bailey's first husband, John Sinfield, drowned while they were on holiday in Barbados in February 2011.

In the months after Stewart reported Bailey missing to police on 15 April, he kept up a pretence that the 51-year-old may still be alive, including pretending she had left a note to say she needed some time away and had gone to her property in Broadstairs, Kent and sending her sent her text messages and emails in a bid to cover his tracks.

Stewart even killed Bailey's pet dachshund, Boris, and buried him alongside her in the cesspit in order to make her disappearance more believable.

helen bailey
Ian Stewart has now been given life for murdering author Helen Bailey Hertfordshire Police

Stewart was also found to have drugged Bailey with sleeping pills Zopiclone, which had been prescribed to him in January 2016. The court heard how Bailey had been complaining about being unusually tired before in the weeks before she was killed. She even made a number of internet searches asking questions such as 'why do I keep falling asleep?', 'falling asleep in the afternoon?' and 'can't stop falling asleep?'.

During the trial, the jury heard how Stewart planned to murder his fiancé in order to gain a "substantial financial advantage" that would arrive from her death, estimated at about £4m ($5m).

Hertfordshire Police told how Stewart had amended a monthly standing order from Bailey's account into his from £600 to £4,000 following her death and twice asked for copies of her will while she was reported missing.

He had also booked snooker tickets with her credit card and went on a holiday to Spain they had booked together while police were still searching for her.

Stewart was also found guilty of murder found guilty of preventing a lawful burial, fraud and three counts of perverting the course of justice.

Helen Bailey
Workers recovering the body of Helen Bailey at her home Hertfordshire Police

Detective Chief Inspector Jerome Kent from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit, who led the murder investigation said: "Ian Stewart is a cold and calculated man who is clearly extremely manipulative. Not only did he kill Helen, he placed her body and that of her beloved dog Boris in a cesspit. These are the actions of a truly wicked man. I am sure there was a significant level of pre-planning by Ian Stewart whose main motivation was money.

"Since his report to police on April 15 that Helen was missing, he has told a significant number of lies to her family and friends, his own family and to police and continued those lies when he gave evidence in court.

"I would like to thank Helen's family who have remained dignified throughout despite Ian Stewart's elaborate story and continuing charade. He allowed Helen no dignity and whilst the right decision has been made by the jury, I am sure this will be of little comfort to Helen's loved ones. Our thoughts remain with them, Ian Stewart's family and Helen's friends."

Ian Stewart
Ian Stewart, moments before he was arrested Hertfordshire Police