TWI ''calculating and callous'' brothers who used chloroform bought over the internet to smother and kill a former Southampton shopkeeper on Christmas Eve will be sentenced today.

Cash-and-carry boss Roger Cooper and ex-Army reservist David Cooper were convicted yesterday of murdering 34-year-old Sameena Imam.

An eight-week trial heard that Roger Cooper spent at least a month plotting to kill his colleague - one of his three lovers - to prevent her exposing their two-year affair.

Both Roger and David Cooper - who are 6ft 5in and 6ft 7in respectively - remained calm and did not look at each other as they were found guilty by a jury at Birmingham Crown Court.

Ms Imam, who was just 5ft 2in, is believed to have been overpowered on a sofa at David Cooper's home in Hughenden Drive, Leicester, between 5.07pm and 6.26pm on December 24.

The victim, who worked at Costco stores in Cardiff, Southampton, Bristol and Coventry, was reported missing by family members in Essex after failing to return home for Christmas, sparking a major police inquiry.

Roger Cooper, 41, and his 39-year-old brother were arrested on suspicion of murder on January 7 - a week before Ms Imam's body was found buried on an allotment in Leicester.

At the start of the trial, it was alleged that Roger Cooper was ''juggling'' relationships with three women, including Sameena and a second colleague, while managing Coventry's Costco warehouse.

The retail worker, of Tilehurst Drive, Coventry, told police investigating Ms Imam's disappearance that he last saw her when she left the store at about 4pm on December 24.

Following yesterday's verdicts, Ms Imam's younger brother, Imran Imam, read his victim impact statement to the court.

As his sister's killers continued to show no sign of emotion in the dock, Mr Imam said he was constantly reminded of her loss, even by everyday items such as signposts for places linked to her death.

Mr Imam told Judge Patrick Thomas QC: ''I worry about the world we live in and the risk that something similar could happen, God forbid.

''I have questions for those who did this. I fear these questions, these open wounds, will never be answered, will never heal.''

The defendants, who face mandatory life sentences, are due to be sentenced by Judge Thomas this afternoon.