The Technology Crime Suppression Division has warned lovers not to video-record their sex on Valentine's Day to avoid being blackmailed after the relationship ends.

Police said on Sunday that lovers often express their passion for one another on Valentine's Day, but they should take precautions – by not recording it on video.

"Lovers may record their sexual intercourse. [But] if they break up in the future, men may release the clips online and damage women," a division commander said.

Such cases fall into the category of "sextortion" by those who have pornographic material of others.

Such private images could be used for blackmail – to demand money or sex – as offenders could threaten to post the pictures or videos in public.

Another love crime is romance scams, where scammers use profiles of handsome foreigners to develop relationships and finally trick their victims into sending money to them, he said.

A third kind is a hybrid scams that involve criminals luring women into falling in love with them – and then convincing their victims into "investing" their money before they were realised they were being scammed.

Police said that last month alone 168 romance scams and 235 hybrid scams had been reported. Total damage in the cases was estimated at about 190 million baht.