With Valentine's Day approaching, the Office of Fair Trading (OFT) has warned of internet dating scams that can leave people heart-broken and out of pocket.

As part of its Scams Awareness month, the OFT said the increased potential to meet new people online is being exploited by scammers to con people out of their money.

Fraudsters generally target online singles columns and dating websites. The online profiles they create are fictitious and are usually accompanied with fake photographs.

In some cases fraudsters have strung people along for years, conning them out of huge sums of money and leaving them financially ruined.

Some of the most serious cases are being investigated by the Serious Organised Crime Agency (Soca). One recent case involved a British national who was kidnapped after travelling to West Africa after falling for a dating scam.

Sharon Lemon, Soca deputy director, said: “No-one should fear using the internet to meet people, but criminals will look for opportunities everywhere and the internet is no exception.

"There is plenty of good straightforward advice out there from sites like Get Safe Online. You don't have to become a victim.”

The Foreign and Commonwealth Office warn the problem is prevalent in West Africa. The fraudsters assume the false identity of a foreign national working and living in West Africa.

In some instances the impostor has informed their foreign friend that they have been hospitalised or arrested and need money quickly. In other cases as with the one above, after being kidnapped the victim is held for ransom.

Fraudsters can even dupe people into acting as money mules or to handle stolen goods. Research carried out by The 3rd Man, an online card fraud monitoring company, found women using dating websites were particularly vulnerable to this scam.

The OFT-managed advice service Consumer Direct said people should be sceptical and ask themselves simple questions. If someone asks for money be suspicious, even if you have been communicating for weeks.

The consumer advice agency said people should ask themselves: "Why am I the only person who can help them, when I have just met them?"

People who sign up to a dating agency should find out what they are paying for and what the agency promises to provide in return. And always meet in a public place and take a friend with you for support if you are unsure.

Heather Clayton, senior director of the OFT’s Consumer group, said: "The internet is now an established way to meet and connect with new people, but those meeting on dating and other sites need to be on their guard against potential dating scams.

“All fraud is destructive but dating scammers are particularly ruthless as they abuse the emotional trust and attachments that people invest when looking to meet someone."

There is more information about Scamnesty on the Consumer Direct website, where people can also send any suspect email or online scams to the online Scamnesty bin.