The City watchdog has admitted mistakenly publishing the details of around 1,600 consumers who complained about it in an embarrassing data breach.
The Financial Conduct Authority (FCA) revealed the personal details of complainants on its website in response to a Freedom of Information (FOI) request, meaning the data was accessible by anyone between November 2019 and February this year.
Data leaked included names of complainants and, in some cases, other confidential details were shown, such as their addresses, telephone numbers and the nature of their complaint.
The regulator said no financial, payment card, passport or other identity details were included.
It removed the information as soon as it became aware of the breach and said it is making direct contact with complainants whose personal details were exposed to apologise and advise them of the next steps.
The FCA said the details were revealed in a section of its website in response to an FOI on the number and nature of new complaints made against the FCA and handled by the complaints team between January 2 2018 and July 17 2019.
The FCA said it has “taken immediate action to ensure this cannot happen again” and has also reported the breach to the Information Commissioner’s Office (ICO).
The FCA said: “We have undertaken a full review to identify the extent of any information that may have been accessible.
“Our primary concern is to ensure the protection and safeguarding of individuals who may be identifiable from the data.”
The breach will likely leave FCA boss Andrew Bailey red faced, as he prepares to take over as governor of the Bank of England next month.
The watchdog itself investigates data breaches within the firms it regulates, while it is also currently probing a security breach at the Bank of England that allowed hedge funds early access to audio feeds of governor Mark Carney’s press conferences.
It also comes after the FCA was fined £2,000 for failing to run its own pension scheme correctly.
The Pensions Regulator found last month that the FCA failed to provide adequate details in its defined contribution scheme documentation.
And an internal memo, leaked to the Evening Standard in November, found that the organisation’s £60 million head office had been reduced to “shameful” squalor.
According to the letter, staff were accused of bad and unhygienic behaviour, including defecating on the floor in toilet cubicles.