But the jury stopped short of finding John William Chardon, 72, guilty of murdering Novy Chardon, a charge that means he meant to kill.

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

Her body has never been found.

Chardon was tried in Brisbane Supreme Court for three weeks before the jury found him guilty of manslaughter on Monday.

The trial heard a raft of sensational allegations including that he had attempted to hire a Filipino hit man.

It heard he was obnoxious, had numerous affairs, and had asked his daughter to hide a mysterious box said to contain gun parts and handcuffs.

He denied it all.

During the trial, prosecutor Mark Green mocked Chardon's version of the events surrounding his wife's disappearance, calling them "Johnny's special stories".

"He thinks that he can get away with murder because he did such a good job at disposing of Novy's body," he told the jury during his closing remarks.

He accused Chardon of murdering his wife after receiving the letter about custody of the couple's two children.

But the jury disagreed and found him guilty of the lesser charge.

Ms Chardon had been deeply unhappy during the last years of her marriage. She was preparing for life outside her husband's "dark shadow", the court heard.

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

The court heard Chardon received the divorce letter at 3pm on the day she later disappeared.

He was waiting in the garage when Ms Chardon returned home that night from dinner with a friend.

"He thought he was being told Novy was going to have control of the children and would control when he could see them," Mr Green said.

"There was no way in the world he was putting up with that ... or the humiliation of finding another place to live, which he really didn't want to do".

Chardon said his wife had ignored him when he confronted her that night.

He said his wife told him she was leaving later that night, so he went to bed.

Mr Green told the jury there was no direct evidence about how the alleged murder occurred. But they heard Chardon had hired a steam cleaner at Woolworths the following morning and cleaned his wife's bedroom carpet.

He then boasted about his cleaning efforts and his sexual prowess to Ms Chardon's best friend, Frederika Wong, who had come to the house. Ms Wong left when he propositioned her.

"The sheer arrogance to do that after you killed your wife that night," Mr Green told the jury.

"Maybe he just wanted to be sure that someone that knew her wouldn't notice whatever it was that happened in that room."

But Ms Wong did notice the wet carpet - and when police began investigating it was urine stains found deep in the carpet's pile that revealed something had happened in the bedroom.

Maybe he "disabled her in some way, (did) something to her in the bedroom that let him get her out of the house and kill her", Mr Green said.

Chardon will be sentenced at a later date.

Australian Associated Press