Royston murderer Ian Stewart was today sentenced to a minimum of 34 years’ imprisonment after being found guilty of killing his fiancée, author Helen Bailey, to get his hands on her £4 million fortune.

Stewart, who is 56 and originally from Letchworth, drugged 51-year-old Helen for months before murdering her and dumping her in a cesspit beneath their £1.5 million home in Baldock Road along with her beloved dachshund Boris.

And passing sentence at a packed St Albans Crown Court today, Judge Andrew Bright told Stewart – who declined to return to court, and will receive the comments in writing – that it was ‘difficult to imagine a more heinous crime’.

Addressing Ian Stewart, who will be 90 when he is eligible for parole, the judge said: “Helen Bailey was only 51 years old and at the height of her success as a writer when you brought her life to a cruel end, and dumped her body and that of her beloved dog Boris in a foul-smelling cesspit to decompose.

“I am satisfied that your principal motive for killing her was to enable you to take advantage of the generous provision she had made for you in the event of her death, which you knew the law would presume after she had remained a missing person for long enough.”

Saying Stewart was ‘a very real danger to women’, the judge referred to the great lengths the killer went to gradually drug Helen so she could not fight him off – and then to conceal the bodies of Helen and Boris in the hope that they would decompose and never be found.

He said: “You deceived Helen Bailey’s family and friends for a period of over three months by a calculated and callous series of lies, which meant that they had to endure the anguish and misery of not knowing her whereabouts or her fate for a long time before the appalling truth emerged.

“You knew Helen Bailey to be a wealthy woman, but were not content with having to share in her wealth as a husband. Instead you wanted it all for yourself.”

The court was told that Helen had assets worth well in excess of £3 million, and had taken out a life insurance policy worth another £1.28 million, from which Stewart stood to benefit.

Stewart was also sole executor and trustee of both the Royston property and Helen’s second home in Broadstairs, Kent.

The judge continued: “I have read the impact statement of Helen Bailey’s brother John in which he sets out the effect which the cruel murder of his sister has had, and will continue to have on him, Helen’s mother and father and her many close friends who all feel an enormous sense of outrage at the way she and her dog Boris met their deaths at your hands.

“As John Bailey rightly observes, the world has lost a gifted author and her family and friends will have to live for the rest of their lives with the deep sense of loss your wicked crime has inflicted upon them.

“Whilst we will never know whether you may have had some additional motive for killing the woman who loved you and wanted to be your wife, I am in no doubt that this is a clear case of a murder done in the expectation of gain, with aggravating features which make it difficult to imagine a more heinous crime.”

A jury of seven men and five women yesterday convicted Stewart of murder, fraud, preventing lawful burial and three counts of perverting the course of justice. Eight jurors returned for today’s sentencing.

DCI Jerome Kent, who led the investigation, has said that he will now also head a probe into the death of Stewart’s wife Diane in 2010.

Diane’s death, from an epileptic fit, was found by a coroner to have been of natural causes.

DCI Kent said it was not a murder investigation, but that it ‘would be quite right’ for him to look again.

Helen Bailey’s relatives have said in a statement that their thoughts are with Ian Stewart’s family.

The statement continued: “Despite this victory for justice there can be no celebration. Our families have been devastated and nothing can ever bring Helen back to us, or truly right this wrong.

“A long shadow of loss has been cast over the lives of so many who will always remember Helen with enduring love and affection.”