Chinese authorities speaking to man over discovery of woman's body in a Sydney freezer

The body of a female Chinese national has been found in a freezer in a Sydney upper north shore unit, with a 36-year-old being quizzed by Chinese authorities.

The crime scene on Wedensday. Source: Network 10

Chinese authorities have confirmed they are speaking to a man linked to the death of Chinese woman found in a freezer in a Sydney unit.

Police discovered the body of the woman - believed to be in her 30s - after they entered the Pymble unit on Wednesday morning.

Emergency services had been called to the unit on Bobbin Head Road about 10am on Wednesday after a friend become concerned for her welfare.

The woman has not yet been formally identified.

The exterior of the apartment building. Source: Network 10

Sources say the woman's husband was also a Chinese national and has left the country with the couple's two children.

Police on Thursday morning said in a statement that a 36-year-old man and two boys, aged four and six, left Sydney on a China-bound flight about 11:30am on Tuesday.

The children are safe and Chinese authorities in the southwestern Sichuan province are speaking with the 36-year-old, NSW Police say.

They are now appealing for anyone with additional information to come forward and will address media on Thursday.

A post-mortem examination will be conducted next week to determine the woman's cause of death.