Yang Zhao, 30, on Monday pleaded not guilty to the murder of Qiong Yan, 29, in September 2020 at their apartment in the inner-Brisbane suburb of Hamilton.
But he pleaded guilty to interfering with Ms Yan's corpse, which was found concealed in a "body box" on their riverside unit's balcony almost 10 months after her alleged murder.
Crown prosecutor Chris Cook told a Supreme Court jury Zhao went on to use Ms Yan's phone to send 2000 text messages to friends and family.
Mr Cook said Zhao allegedly impersonated Ms Yan to steal more than $700,000 after her death.
The jury was shown part of the videos from Zhao's two police interviews after Ms Yan's body was found when officers entered the apartment on July 19, 2021.
"I sat in front of her and hit her on her head three times," Zhao told police in a video-recorded interview on July 22.
"I think I go crazy. I ask her why she wouldn't die."
The jury was told they would see videos of Zhao telling police Ms Yan wanted him to kill her as part of a suicide pact.
Mr Cook said Zhao made those claims without evidence after "months of lying" to police about Ms Yan's whereabouts.
Zhao told police Yan asked him to choke her.
"I choked her for about half an hour or an hour. I can't remember," Zhao said.
The jury heard evidence Zhao drove to a nearby hardware store and bought a 240-litre toolbox, duct tape and work gloves with cash.
Mr Cook said police found Ms Yan in the "body box" after entering the apartment on a missing persons warrant.
"The term 'body box' is Mr Zhao's own words,," Mr Cook said.
The jury was shown a photo of Ms Yan as she was discovered, curled up in the toolbox underneath a black sheet with one foot exposed.
Mr Cook said Zhao loved the high life and before the alleged murder had unsuccessfully gambled on the stock market and on poker, losing up to $100,000 at a time.
"(Zhao) needed money. He lost money. He killed (Ms Yan). He posed as her for a while. He took her money," Mr Cook said.
Mr Cook said Zhao took control of Ms Yan's phone, placing black tape over its cameras.
The jurors were told they would see Ms Yan's mother had sent a total of $411,000, while $200,000 in cash withdrawals were made from Ms Yan's bank accounts after she had died.
Mr Cook said Zhao transferred Ms Yan's $300,000 Porsche Panamera SUV to his own name and later sold it.
"Zhao never had a job, he never lodged a tax return. He was in arrears for rent," Mr Cook said.
Zhao at the time of the alleged murder was a Chinese national living in Australia on a student visa.
Ms Yan was also a Chinese national living on a bridging visa and was a migration agency director.
Ms Yan's friend in Sydney filed a missing persons report to NSW Police after months of receiving strange messages.
The jury heard Zhao was at the time of Ms Yan's death inhaling nitrous oxide gas to get high and consuming alcohol.
Zhao's barrister, Andrew Hoare, told the jury they would need to listen carefully to how his client described Ms Yan's death in the police interviews.
"You may think that event is unique to Mr Zhao to such an extent that those facts out to be etched indelibly in Mr Zhao's memory," Mr Hoare said.
"Some parts of the interview got to the point that Mr Zhao's memory was not as indelible as you would expect from a person who was recounting true events."
The trial continues.
Lifeline 13 11 14
beyondblue 1300 22 4636
14°C