The chief financial officer of Revolut, one of Britain’s best-known financial technology companies, resigned in January as the company was grappling with questions over its compliance systems, it emerged on Thursday.

Peter O’Higgins, who joined the ­digital bank in 2016 after 12 years at JP Morgan, quit the company at the start of the year, Revolut confirmed.

The start-up, however, insisted last night that Mr O’Higgins’ resignation was unconnected with concerns raised over compliance.

Details of his departure emerged one day after The Telegraph reported that Revolut’s board had launched an internal investigation last year into a “failing” in the bank’s sanction screening system.

A whistleblower contacted the bank’s board last year to inform them that an automated system to block transactions flagged for further checks had been turned off for months.

Documents seen by The Telegraph show that thousands of transactions flowed through the digital bank’s systems between July and September last year before they were checked for sanctions compliance after a decision to disable the blocking mechanism.

Mr O’Higgins’ departure is the latest blow for Revolut, which since its launch in 2015 has grown into the UK’s largest app-only challenger bank.

His lengthy experience in the financial sector has been valuable for the start-up which has attracted 3m customers.