Some who have been the target of the scam but escaped have shared their experiences on social media, warning others. Others have not been so lucky, however.

One mother lost close to £1,000 to a criminal gang posing as her daughter, Santander said. WhatsApp messages from the scammers said the girl had changed her phone number and that she needed money to buy a new laptop as the bank had put a 48-hour block on her account.

The woman, who was abroad at the time, gave into the requests. She then revealed another message thanking her and telling her to enjoy her trip – an effort from the gang to throw her off the scent and avoid her twigging and calling the bank to block the payment.

Chris Ainsley, of the bank, said the volume of the scams had “skyrocketed over the past few months”. “By preying on people’s relationships with their loved ones, while simultaneously applying immense pressure, these crooks are successfully getting into people’s heads and persuading them to hand over their hard-earned cash,” he said. 

The bank found that scammers posed as sons in two thirds of cases and as daughters in need the rest of the time. 

Kathyrn Harnett of WhatAapp said customers needed to be vigilant of potential financial crime. “We advise all users never to share their six-digit PIN code with others, not even friends or family, and recommend that all users set up two-step verification for added security.

“And if you receive a suspicious message (even if you think you know who it’s from), calling or requesting a voice note is the fastest and simplest way to check someone is who they say they are. A friend in need is a friend worth calling,” she added.