Luxury watch dealers and jewellers who ply their trade on WhatsApp are being targeted by an army of scammers who threaten to get them banned from the platform unless they pay thousands of pounds in ransom.

Small business owners told The Telegraph that their WhatsApp accounts had been banned without explanation. They said that both before and after the bans they had been contacted by anonymous accounts demanding payment in cryptocurrency, either to leave the victims alone or restore access.

Thanks to its privacy and ease of use, the Meta-owned messaging app has been adopted by a legion of entrepreneurs who use it to market expensive watches, chains and other jewellery, contact customers, conduct details and store records.

With prices for some watches reaching into the tens of thousands of pounds, having their account disabled for a matter of weeks can result in a significant amount of lost income.

The businesses say Meta is doing little to help, leaving their operations hamstrung while they rack up losses and fall behind competitors.

It has also emerged that the contact form for businesses on WhatsApp’s help page is broken, making it harder for them to report problems.

When the issue was brought to Meta’s attention by The Telegraph, the company said it had flagged the issue internally.

Tony Singh, who runs Asian Wealth Jewellers, a luxury watch and jewellery dealership that trades in the UK and Canada, received messages in early August from a scammer threatening to have his WhatsApp account banned unless he paid a “ransom”.

Mr Singh refused, and woke up the next day to find his account out of action. He said: “I was in limbo. It really affected me, personally, business and financially.”

During the time he was banned, Mr Singh communicated with numerous social media accounts claiming to be able to unban his account for a fee. Many of these viewed by The Telegraph appear to originate from India.

He said: “There’s a huge network of people that use Meta for business, whether it’s Instagram, Facebook, WhatsApp, it’s used as part of our daily lives. When you take them away … what do you do?

“[If you] start again you lose everything that you’ve got.”