An unfaithful husband who bludgeoned his wife to death and left her body to rot in a plastic car roof box in the garden of the family home will be sentenced today.

A jury took less than two hours to convict Andre Genestin of using a mallet to crush the skull of his wife Catherine, 38, as she sat on their lounge sofa then hid her body in and around the house.

In the weeks after the murder, which happened some time over the weekend of May 11 and 14 last year, French national Genestin carried on life as normal.

He attempted to allay the concerns expressed by family and friends by insisting his wife was prone to disappearing and she would return home to Maresfield Road, Brighton, in a few weeks.

Judge Anthony Scott Gall, sitting at Lewes Crown Court, said unemployed Genestin, 48, had been convicted on the "most compelling evidence".

During the two-week trial, jurors heard it was only after the couple's young daughter repeatedly raised her concerns about her mother's disappearance with her teachers that social services and the police investigated.

Police officers drawn to a strong smell from the car roof box in the back garden of the couple's home found the decomposed remains of 38-year-old Russian-born Mrs Genestin.

Examination of Genestin's computer after he was arrested showed he had been composing a letter to the British consulate in Kiev stating he would be sponsoring a woman called Tatyana to come to the UK.

As his wife's body lay at the property for up to six weeks, Genestin was pursuing ways to help Tatyana's entry to the UK, including producing false files claiming she had secured a place on an English language course.

Genestin could have killed his wife because she would have been in a position to blackmail him if they were to separate because of what she knew about his dubious business dealings, prosecutors said.

Genestin had denied murder but admitted manslaughter by reason of provocation.

In evidence, he claimed he had been driven to killing his wife, saying there was "only so much hysteria a man can take".

He said: "I have to protect my daughter and myself. I have a high threshold in coping with emotional pressure. I think your average man would have cracked before I did."

Following his arrest, Genestin made no comment to all questions put to him and he was charged with murder on June 29, 2007.

After being remanded to Lewes prison in East Sussex, Genestin requested a visit from church elder Alan Preston and confessed to him that he had killed his wife.

Genestin told Mr Preston he had been mending a leg on a sofa with a mallet when he felt "emotionally tormented" by his wife and attacked her.

He had prepared himself for the possibility that police might find out his wife was dead by reading books on how to eliminate traces of forensic evidence and on how to deal with police interrogations.