Annabelle Chen was unaware her ex-husband had maintained a relationship with their daughter, so they argued when he visited her Perth home to discuss attending a university graduation ceremony - and it cost Ms Chen her life.
Bankrupt businessman Ah Ping Ban, 69, bashed Ms Chen with a blunt object then stuffed her body in a suitcase, using a scooter with a breadboard attached to move the luggage and dump her in the Swan River.
A jury found Ban guilty of murder and he was sentenced in the West Australian Supreme Court today to life behind bars with a minimum of 20 years.
The former couple's daughter, 27-year-old Tiffany Yiting Wan, was found guilty of being an accessory. She was sentenced to four years and 10 months in jail, but with time already served could be granted parole in July.
Before the trial, Wan offered to plead guilty to being an accessory and testify against her father, but prosecutors rejected it.
At trial, the pair blamed each other for killing the 58-year-old at her Mosman Park home in mid-2016.
Ban claimed Ms Chen was already dead when he arrived in Perth from Singapore on June 30 and he only helped dispose of the body at the Fremantle Traffic Bridge.
But Wan testified she heard Ms Chen scream and a "loud metallic thud" sound, then her father later confessed to killing his ex-wife with a cast-iron paperweight.
Justice Joseph McGrath accepted Ban did not go to Ms Chen's house intending to harm her, but during an argument he repeatedly struck her using a blunt object in a "violent physical assault".
Ms Chen suffered 25 head injuries, including a fractured skull.
Justice McGrath said Ban "displayed a callous indifference to the body" and no remorse.
He rejected Wan's claim her father drugged her, but accepted she did not help dump the body.
"You had full appreciation of what was occurring," Justice McGrath said.
He said Wan was not coerced but had been motivated by misguided loyalty to her father when she helped cover up the crime.
That included cleaning footprints, washing clothes, helping replace a mattress, sending text messages to make it seem Ms Chen was alive, and lying to police.
After the murder, Ban and Wan returned to their respective homes in Singapore and Melbourne.
Two fishermen found Ms Chen's body on July 2, 2016 but her identity remained a mystery for two months until Wan reported her missing.
Wan cried several times during the trial including when the jury was shown X-ray images of her mother's injuries and while testifying.
But she appeared less emotional during sentencing.
Ban's lawyer David Brustman said it was possible Ban would have little or no life left outside jail given his age.
Wan's lawyer Simon Freitag told reporters his client wanted to get on with her life.
"We're pleased that it's come to an end," he said.