A man has been charged with the murder and kidnapping of his mother following an investigation in Sydney’s north-west earlier this week.

Police began looking into the disappearance of 58-year-old Sandra Popovic on Tuesday, June 9, after she had not returned home after telling family she was meeting her estranged son, Ante Popovic, at a Winston Hills carpark. Sandra Popovic, 58.

Police say Sandra Popovic’s body has not yet been found. Supplied

Family members told police they’d last had contact with her at about 4.50pm on Monday, the afternoon before.

Superintendent Barry Vincent said police will allege the pair were meeting to talk about borrowing money.

“We don’t know whether that exchange occurred … but we will allege communications towards the missing lady were hostile in nature,” he said.

He added that police held “significant concerns” and are now turning to the public, particularly in Winston Hills, for help locating the 58-year-old. Superintendent Barry Vincent is turning to the public for help finding the mother.

Superintendent Barry Vincent is turning to the public for help finding the missing mother. 9News

Her car was found on Dodson Street in the same suburb at about 9.30am the next day.

At about 1.40 pm yesterday, police arrested 33-year-old Ante Popovic, who is known to police, sitting in a white Toyota Hilux dual-cab utility in bushland along Parnell Fire Trail, Tomerong, about 20km south of Nowra on the NSW South Coast.

Vincent said police were able to find him after the missing woman’s phone was allegedly “co-located” with him as he travelled towards regional NSW.

A search warrant was later carried out at an address in Sanctuary Point, about 25km south of Nowra.

The 34-year-old has been charged with murder and kidnapping and was refused bail to appear in court again in August.

he body of Sandra Popovic has not been found, and the investigation is ongoing.