A police spokeswoman said none of the three men involved in the latest three cases tendered any payment.

“He told police he was filmed during an online video chat with a woman and then ordered to pay HK$50,000,” the spokeswoman said.

The second victim was a 20-year-old man who lodged his complaint with police in Kwai Chung at about 10.45am today.

Police figures showed there were 506 local reports of ‘sextortion’ in the first six months of this year – more than eight times the 60 cases reported for the whole of 2012.

In 2013, there were 477 cases, and last year there were 638.

Police are treating the three cases as “blackmail”.

He was also filmed, at his home in Hung Hom, during an erotic online video chat with a woman.

He was told that if he did not pay HK,000 the footage would be circulated online, police said.

Police received the third report from a 33-year-old man in Tai Po at about 12.15pm.

“He was asked to pay HK,000 otherwise his naked photograph would be posted on the internet,” the spokeswoman said.

According to police, the amount the victims paid in the crimes also increased to HK.6 million in the first six months of this year, up by a factor of ten from HK0,000 for all of 2012.

Swindlers pocketed HK.7 million through such online naked chat blackmailing in 2013 and took in HK.3 million last year.