On September 8 an 18-year-old woman was reported missing to police by friends concerned for her welfare.

Police were told videos and images of the woman, who was being held at an unknown location, had been sent to family members overseas via WeChat.

The videos were followed by demands for money by a person purporting to be Chinese police to ensure the woman's safe release.

The State Crime Command's Robbery and Serious Crime Squad, together with local detectives, began investigating along with police negotiators, the AFP and Chinese authorities.

Detectives found the woman safe and well at Pyrmont last Tuesday before raiding a unit at Chatswood on Sydney's north shore.

A 22-year-old man was spoken to by police and inquiries into the incident are continuing.

NSW Police Force State Crime Command director, Detective Chief Superintendent Darren Bennett, renewed recent warnings about elaborate virtual kidnapping scams targeting Chinese students studying in Australia.

"It appears these scammers are continuing to operate and are once again preying on the vulnerabilities of individuals in the community who are not in direct physical contact with their families," he said.

In the latest incident initial contact was made in July when the woman received an email purporting to be from Chinese police, saying her personal details had been illegally used on a package intercepted overseas.

"Since that time more than $213,000 has been transferred into an offshore account following demands for money, which appears to have evolved into a virtual kidnapping," Det Supt Bennett said.

"The individuals behind these virtual kidnapping scams continually adapt their scripts and methodology, which are designed to take advantage of people's trust in authorities."

Anyone who received a call demanding money under the threat of violence should hang up, contact the Chinese consulate in Sydney to verify the claims and report the matter to police.

Australian Associated Press