Adverts for Binance, which boasts of being the world’s largest exchange for cryptocurrency, are everywhere.

The company describes its service, allowing investors to buy bitcoin and all other kinds of digital currencies, as secure, fast and elegant. You can buy and sell in minutes.

It is not alone. The bitcoin bubble has led to a rash of cryptocurrency trading platforms springing up online. Their names are on the sides of buses, on advertising hoardings at sports events and on the shirts of Premier League football teams.

But concerns are growing that cryptocurrency trading sites allow fraudsters to set up an account in minutes without checks, leaving them free to hide money stolen through scams.

The fight against scammers has become a global battle waged by