John Chardon jailed for 12 years for wife's death

A Gold Coast millionaire who killed his estranged wife amid a bitter row over the custody of their two children will spend at least the next 12 years in prison.

John William Chardon, 72, was convicted of Novy Chardon's manslaughter following a three-week trial in the Brisbane Supreme Court.

The mother-of-two, 34, disappeared from their Upper Coomera mansion on the night of February 6, 2013.

Her body has never been found.

On Wednesday, Justice Ann Lyons sentenced Chardon to 15 years in prison, with parole eligibility in 2031.

His trial heard a raft of sensational allegations, including that he had attempted to hire a Filipino hit man, had numerous affairs and asked his daughter to hide a mysterious box said to contain gun parts and handcuffs.

He was also accused of murdering his wife hours after receiving a letter from her divorce lawyer about the custody of their children.

But Chardon denied it all, saying Ms Chardon told him she was leaving.

The court heard the Indonesian-born beautician had been deeply unhappy during the last years of her marriage and was preparing for life outside her husband's "dark shadow".

She disappeared at the end of the couple's year-long legal separation, during which Chardon stayed in their home to help with the children.

Prosecutor Mark Green had no direct evidence about how Ms Chardon's alleged murder occurred.

Instead, he told the jury it was the "little things" like Chardon hiring a carpet cleaner the morning after Ms Chardon disappeared and his brief journey to his factory the night before that proved his guilt.

However, the jury found Chardon guilty of the lesser charge.