The hacks have led to illicit activities such as opening bank accounts and applying for loan.
More than 750 fake businesses, often with misspelled names, have been registered in the past six weeks, prompting an investigation by Companies House, the UK's central registry of companies.
Fraud expert Graham Barrow shared detailed data with the BBC, calling Companies House "not fit for purpose" and pushing for more rigorous checks.
He added: "There's been this rise of identity theft, and the requirement for all of us to provide bills, passports or a driving licence, even if you want to get a library ticket from your local council.
"Companies House requires none of that."
He also said it was "scandalous" the situation has been allowed to continue "without any intervention whatsoever".
Scammers can easily register a business online for a small fee, enabling them to steal overdraft money, order high-value goods, and leave invoices unpaid.
So-called ‘clone restaurants’ often have names similar to authentic establishments, sometimes with slight misspellings, contributing to the confusion.
Mr Barrow criticised Companies House for its lax verification processes, emphasising the rising threat of identity theft.
While new powers to combat fraudulent registrations will be granted to Companies House next month, implementing stricter checks will take additional time.
Heston and Yotam both had their restaurant identities cloned, with scammers registering businesses with slight variations in names.
The Ritz Hotel’s restaurant, in operation since 1906, also faced identity theft, with a new company registered in December 2023.
Mr Barrow said the scams were leading to financial losses by banks – estimated to be in the hundreds of millions.
The government and Companies House are aware of the issue, but full changes to address the problem are expected to take at least 18 months. In the meantime, criminal networks from around the world continue to target the UK through "clone company" schemes.
Companies House expressed regret for the challenges faced by businesses and outlined plans for future changes, including identity verification for company directors and information filers.
It said: “In the longer term we will be requiring company directors and people who file information to verify their identity to ensure they are who they say they are.
“These changes will enable us to crack down on the use of false addresses and other misuse of the register.”