Two mainland Chinese students studying in Australia were duped out of more than HK$12.7 million (US$1.6 million) by phone scammers and tricked into going to Hong Kong to stage a bogus kidnapping for a multimillion-dollar ransom.

Police on Friday revealed they had deployed more than 100 officers to search for the two young women, who were eventually found alone in a hotel room, with a knife, rope and syringes they had bought themselves. One of the women had been cut on her arm several times in a bid to make the abduction look more realistic, according to police. No arrests have yet been made.

The two women, who study at the same university in Sydney but do not know each other, were first contacted by the scammers in March. Posing as mainland police, the fraudsters ordered the pair to transfer funds as part of a bogus investigation.

The younger victim, 22, was later tricked into believing her father was caught up in criminal activities and that a staged kidnapping could help draw out members of a gang the fake mainland officers were supposedly hunting. The older woman, 23, was persuaded to escort the other victim to Hong Kong, where the ruse would take place.

The pair met in Sydney before flying to Hong Kong last Sunday, according to the force.

Crime squad officers pored over a large amount of security camera footage to track them down to a Tai Kok Tsui hotel room on Thursday afternoon, where they were rescued about three hours after one of the families filed a report to police.

On Wednesday, the father of the younger victim received a video via messaging platform WeChat showing his daughter bound and blindfolded with a demand for 14 million yuan (US$2 million) ransom.

An identity card seized as evidence by police.

“In the video, someone’s hand can be seen holding a knife and cutting her left arm multiple times, causing her to scream for help,” a source familiar with the case said.

The family immediately sought help from Australian authorities but were told the 22-year-old had left the country for Hong Kong. Her elder brother then travelled to the city from the mainland and went to Mong Kok police station to file a report at around noon on Thursday.

After a three-hour investigation involving the deployment of more than 100 officers, police tracked them down to the hotel.

The force went to the location at around 3pm. “Officers broke into the hotel room and rescued the two victims,” said Chief Inspector Chow Chun-choi of the Kowloon West regional crime unit. No ransom was paid.

He said the younger woman suffered cuts on one arm and the other was unhurt, adding that a knife and ropes were among other items seized at the scene.

In March, the fraudsters posing as mainland police contacted the two women and accused them were involved in money laundering. The duo were asked to transfer money into designated bank accounts on the mainland that month and in April for further investigation.

The younger woman, whose family runs a logistics company on the mainland, was told to lie to her father by claiming that the university needed to ensure her family could provide enough financial support for her to continue studying in Sydney. She then asked him to transfer money to her.

The scammers called the two women and posed as mainland Chinese police officers.

According to police, she lost A$2.3 million (US$1.5 million), while the other woman lost 600,000 yuan.

The bogus mainland police later contacted the younger woman again and said her father was involved in illegal activities and associating with the ringleader of a criminal gang.

“She was told that a kidnapping could help lure out those behind the criminal gang,” Chow said.

She was then tricked into coming to Hong Kong to stage the kidnapping. The fraudsters asked the other woman to work as a “spy” and escort her to the city.

Superintendent Alan Chung said he believed that the scammers wanted to stop the pair from seeking help from their friends and teachers in Australia.

According to police, the pair had not been locked inside the hotel room as they had gone out to buy food and items such as a knife, ropes and syringes used to stage the bogus kidnapping.

Condemning the scammers as “shameless”, Chung said a knife was used to cut the arm of the younger victim multiple times in an effort to make the video more realistic.

He said it was lucky the women were rescued before a solution was injected into the younger victim.

No arrests were made in Hong Kong. Officers said they believed people behind the scams were not based in the city.

Police said they would seek help from mainland and Australian authorities for a follow-up investigation.

The force urged the public to verify the identity of anyone who contacts them.

In Hong Kong, officers handled 2,831 reports of phone scams involving HK$1.08 billion last year. There were 1,140 cases in which phone scammers bilked HK$811 million in 2021.