Mr Abraham, 33, was found dead in his pyjamas and foaming at the mouth and was initially thought to have suffered a heart attack. But an autopsy later revealed he died of cyanide poisoning, and after a lengthy police operation Kamalasanan and Sam were charged, tried and found responsible. "This is a very serious example of the crime of murder," Justice Paul Coghlan said at sentence. "Sam Abraham was a young man asleep in bed at home with his family when he was killed by the use of poison. Sam Abraham was killed by his wife Sofia Sam.

"I am satisfied that the poison was chosen as your murder weapon in an attempt to avoid detection." Detectives used a long lens to spy on Sam and Kamalasanan for months after the death, watching them meet for lunch and run errands. They also found a secret diary that Sam shared with Kamalasanan, illustrating their "deep" feelings for each other. "It was a major part of the prosecution case that both of you had been in a long-term relationship, notwithstanding you both being married," Justice Coghlan said. Arun Kamalasanan being led into court in February. Credit:Jason South

During the trial, diary entries the pair wrote were read to the jurors, who heard whimsical words of their forbidden love. "Can you hold me tight? I want to drift away in your love," prosecutor Kerri Judd QC read from one of Sam's diary entries. "She is the best match for me – but what to do? I am sure that one day she will be mine," Kamalasanan wrote. The killers were both born in India, in the state of Kerala, and met at Mahatma Gandhi University, where both studied science.

The trial had heard that Sam moved with her six-year-old son to Australia from India in 2012, with Mr Abraham joining his young family a few months later after working in Dubai. All the while, prosecutors said, Sam had been having an affair with Kamalasanan, who she'd known for years. Kamalasanan had left his wife and child back in India and moved to Melbourne in the middle of 2013. “Both Sofia Sam and Arun Kamalasanan had a motive to kill Sam Abraham. They both wanted to be together,” Prosecutor Kerri Judd QC had told the trial. At the family home in Epping on October 14, 2015, Sam claimed she awoke from the bed she had been sleeping in with her husband and son to find Mr Abraham, described by Ms Sam’s sisters as a loving family man, dead. She said she thought he'd suffered a heart attack and her wails could be heard in the background in a distressing triple-0 call played to the jury.

But at the heart of the prosecution case against Sam was apparent implausibility that she could have been unaware that her husband, in bed beside her, had been poisoned. AAP, with Adam Cooper