An extortion scam targeting international students from China, previously seen in a number of Canadian cities, has surfaced in Montreal, police say.

"The victim is usually persuaded to pay, and it's really considerable sums of money," said Det.-Sgt. Maya Alieh, a supervisor in the Montreal police service's cybercrime unit.

Alieh said police know of a few recent attempts to scam Montreal-based students, but "cannot put a number on how many events are happening."

The scam involves a call to the students from someone claiming to be a government or police official in China and warning of a threat to a family member.

'Trust me, the police will never ask you to go somewhere without notifying a loved one.' - SPVM Det.-Sgt. Maya Alieh

To save the family member — who is, in fact, completely safe — the student is told to go into hiding and fake their own kidnapping on video.

"Usually the victim is asked to leave right away their house or work or university class, prepare their luggage, not giving an explanation to anybody, just leaving without notifying any living soul what they are doing," Alieh said.

Once they have the faked kidnapping video, the scammers use it to extort ransom money from their family in China.

"Then the money transfers start because the family obviously are very worried about their loved one," Alieh said.

Alieh said various police forces in Canada and abroad are investigating, but it's still unclear who is behind these virtual kidnapping crimes.

"I suspect there are criminal groups in certain parts of the world, as we've seen in other extortion cases," she said. "But these investigations are ongoing, so nobody is divulging anything."

Anyone who receives a suspicious phone call should not give out any personal information and should contact Montreal police, Alieh said.

"If you receive a call, trust me, the police will never ask you to go somewhere without notifying a loved one."