ONLINE dating is fraught with danger at the best of times, but nobody expects to be chatted up then blackmailed into handing over cash.

Police in Victoria have released images of a man in his 20s they say used a dating app to meet people then threatened to reveal their secrets.

A 29-year-old man went to police after an online meeting went wrong. He says he was chatting to various people via the app when a threatening message appeared on his phone.

It told him that if he did not hand over a substantial amount of money, personal information he had just shared would be made public.

The victim agreed and the meeting took place at Southern Cross railway station at about 4.10pm on March 2. What the blackmailer didn’t realise is that CCTV captured the interaction.

Victoria Police media officer Belinda Batty told 3AW it was not clear whether the victim was in a relationship when he was blackmailed.

“I don’t know if this is about a partner,” she said. “This could be about anything. He could’ve been having a discussion about something and then he might not have wanted anyone else to know.”

Police have described the suspect as 181cm tall with a slim build and messy brown hair. His fingernails were painted purple and he wore brown cargo pants, a white T-shirt and a grey shirt and a was carrying a brown satchel across his body.

Anyone with any information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au