The majority of those tricked in "rom-cons" after meeting people on dating sites lost more than £2,000, research by Barclays suggests.

Fraud experts have said that thousands of people have lost millions of pounds in online dating scams.

Barclays found those aged 45 to 64 were most likely to be victims, according to reports it has received from people tricked into making payments.

Dating site users are being urged not to take everything at face value.

The bank suggested that many people were judging those they met online based on their social media profile, their job, or simply trusting them too soon.

"While millions of us take to dating websites and apps to find true love, criminals are getting ready to pounce on anyone who lets their guard down," said Jodie Gilbert, head of digital safety at Barclays.

"We must all remain aware whilst looking for the warning signs, such as someone asking you to help them out of an 'unfortunate situation' by sending money."

The bank said its figures showed that 37% of those who had lost money had paid more than £5,000 to a fraudster.

The BBC has highlighted a number of cases in recent years including one woman who lost more than £300,000 and said she felt emotionally "brutalised". She thought she was paying money to her new love interest for food, rent and medical bills.

In another case, a lonely 86-year-old man said he was left suicidal after a woman he messaged through online dating, but had never met, conned him out of £6,000.

Online safety advice

Criminals who commit romance fraud trawl through profiles and piece together information such as wealth and lifestyle, in order to manipulate their victims

Police can investigate and help to provide support, but often cannot get the money back

It is very simple for fraudsters to cover their tracks by masking IP addresses and using unregistered phone numbers

Never send money to someone online you have never met

Think twice about posting personal information which could be used to manipulate or bribe you