And a spokesperson added in a statement: “We are working to gain clarity from Uber on whether any of the issues seen in the US have occurred here.
“We are pressing them for the full details of what has happened so that we can be satisfied that all the right protections are in place for the personal data of drivers and customers in London.”
Mayor of London, Sadiq Khan, said: “Today’s news is of real concern. I’ve asked the Transport Commissioner to speak with Uber urgently to gain clarity on whether any of the issues seen in the US have occurred here.”
Bloomberg reported on Tuesday that Uber concealed for more than a year the exposure of data relating to 57 million drivers and users, paying hackers $100,000 (£75,500) to delete the data and stay quiet.
The Information Commissioner said it had “huge concerns” over the breach. It is unclear how many of those affected were in the UK.
“None of this should have happened, and I will not make excuses for it,” Dara Khosrowshahi, the firm’s new CEO, said in a statement. “We are changing the way we do business.”
The firm, which brought in Khosrowshahi after a series of PR blunders, lost its London operating licence after a shock decision in September.
‘Not fit and proper’
“TfL has concluded that Uber London Limited is not fit and proper to hold a private hire operator licence,” the regulator said at the time.
While Khan previously commented: ”...all companies in London must play by the rules and adhere to the high standards we expect.”
Maria Ludkin, GMB Legal Director, said: “Once again a further problem with Uber’s operations has been revealed despite their efforts to conceal this massive hack of sensitive data of both customers and drivers.
“When will Uber start telling the truth about their many issues to regulators and the public?”
A City Hall source told HuffPost on Wednesday that it is unlikely Uber’s licensing appeal would be directly impacted by the data hack as the legal process will consider only specific criteria.
TfL highlighted public safety concerns among its reasons for revoking the app’s ability to trade.
Uber’s 40,000 London drivers can continue to use the app during the appeal process.
The challenge was lodged just hours before an official deadline last month and is seen as a legal formality by both TfL and Uber, which have held face-to-face talks to thrash out a new deal.
When asked about how long the appeals process could last at a monthly question session last week, Khan said: “My understanding is that it could go on for a number of years.”
A formal hearing is scheduled for December 11.
Uber has yet to respond to HuffPost’s request for comment.