Chinese authorities have located Haoling Luo, who left Australia this week the day before his wife's body was found stuffed inside a freezer in a Sydney apartment.

Key points: Neighbours said they heard screaming in the couple's apartment on Sunday

Neighbours said they heard screaming in the couple's apartment on Sunday Mr Luo worked as a real estate agent after coming to Australia as an international student

Mr Luo worked as a real estate agent after coming to Australia as an international student He chose to settle in Pymble because he was impressed with local schools

Mr Luo cleared customs at Sydney International Airport on Tuesday with their two young children, who NSW Police say have been located safely in China.

Local authorities in China's Sichuan province are speaking to him.

Officers bashed down the door to the couple's apartment at Pymble, on Sydney's Upper North Shore, on Wednesday morning after concerns were raised for Renxi Ouyang's welfare.

Neighbours told the ABC they heard yelling, screaming and what sounded like furniture being thrown around the home on Sunday night.

Homicide detectives spent last night interviewing neighbours and residents in the area to try and establish a motive for the alleged murder.

Police forced their way through this door to get to Ms Ouyang's body. ( ABC News: Mark Reddie )

The ABC understands Mr Luo, who also went by Andrew, received his real estate licence in mid-2018 and was selling houses in the Upper North Shore before he left for China.

Former colleagues described him as a reserved man, who had a pragmatic outlook in life but was pleasant in his day-to-day interactions.

Real estate agent George Carey sold him and Ms Ouyang their Pymble apartment at the end of 2016 for just over $900,000.

Mr Carey recalled Mr Lou was eager to settle in the region because he was impressed with the local schools.

One person, who did not wish to be named, said Mr Luo came to Australia as an international student at Macquarie University and made regular trips to China where he owned a restaurant.

Haoling 'Andrew' Luo worked as a real estate agent before he left for China. ( Supplied )

Homicide Squad Commander, Detective Superintendent Scott Cook said police did not yet know the motive behind the suspected murder.

"We don't even have a positive identification in regards to the woman [and] we don't anticipate a post-mortem will be undertaken until next week at the earliest," he said.

The detective said they would continue liaising with their Chinese counterparts about their discussions with Mr Luo.

He said he was questioned by local police in Sichuan province, but said it was not clear what Chinese authorities were asking him.

"We anticipate in the course of the day we'll get some feedback on that," he said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 48 seconds 48 s NSW Police says its first priority is the safety of the children. ( ABC News )

Both Mr Luo and Ms Ouyang are believed to be in their 30s.

The crime scene is across the road from Sacred Heart Catholic Primary School.

Parents and neighbours who became aware of the death last night or this morning said they were "devastated".

"It's such a good neighbourhood, we've been here for six years and this kind of has never happened," said Claire Kim.

"I was quite shocked to hear about the news."