Equifax has finally admitted that the data of UK consumers might have been stolen in the massive data breach last week.

The firm said information about some British people had inadvertently been stored in America and that these details had "potentially" been stolen in the attack.

The credit reference agency said it would write to "fewer than 400,000" UK consumers to "offer them appropriate advice and a range of services to help safeguard and reassure them".

For the past week Equifax has refused to say how many British citizens may have had their data compromised and what information could have been stolen.

It did reveal that hackers had exposed the personal data of 143 million customers in the US, which had been unlawfully accessed between mid-May and July this year thanks to a vulnerability on its website.

On Friday it said its UK systems had not been affected but that a "process failure" had led to a file containing information about British consumers being stored in the US between 2011 and 2016.

This file, which contained names, dates of birth, email addresses and telephone numbers of UK consumers, may have been unlawfully accessed, the company admitted. It said the file did not include any addresses, passwords or financial information.

Because of the nature of the data, Equifax said it believed "identity takeover is unlikely" for those UK consumers affected but it would be offering "reassurance and protection" to anyone who had had their information accessed.