Police in Richmond are warning about a sudden spike in the number of cases involving sexual extortion, including a recent jump in cases involving men.

According to the Richmond RCMP, the number of reported cases of sextortion nearly tripled from five in 2013 to 13 last year. Police are asking victims and potential victims to come forward and help them put a stop to it.

Const. Dennis Hwang says there have already been three reported cases this year, all involving men, and there may be more.

"It is very concerning for us primarily because they [the complaints] have come in a short period of time," he said. "We determined it was best to inform the public that this type of behaviour is happening."

Police say these cases of sexual extortion usually begin with someone befriending a potential victim online and enticing them to perform intimate acts in front of a webcam or mobile device.

The extortionist secretly records the act and then blackmails the victim — demanding money and threatening to release the video online if it isn't sent.

Cst. Hwang says contact is often made thorough free social media or dating sites and many victims never report what has happened.

"Speaking to somebody about it, is the best way you may be able to deal with such a a sensitive subject," he said.

Hwang says the Richmond RCMP's serious crimes unit is also involved in the investigation.