AFP/London

London's Metropolitan Police on Friday warned singletons to beware of online dating scams after two men were convicted of duping a woman out of £1.6mn ($2.4mn).

The woman met, via a dating site, a man who claimed to be a well-off engineer. He and his associates subsequently talked her into lending them the money over a period of 10 months, the police said in a statement.

Detective Chief Inspector Gary Miles of Falcon, a specialist police cyber crime and fraud unit, said victims of such scams were being "ruthlessly manipulated" by fake lovers.

The unit has dealt with what the police called "romance fraud" involving 100 victims this year alone.

George Kidd, head of the Online Dating Association (ODA), said: "This heartless behaviour defrauds people but can also rob them of their confidence and dignity.

"We commit to do still more with better information-sharing with the police, through mobile and other ways of verifying identities and with new advice and guidance," he said.

The police issued a seven-point plan to warn people using online dating sites including the tips: "See through the sob stories", "Don't be fooled by a photo" and "Question their questions".