The sudden departure of two veteran Deutsche Bank executives is linked to a continuing investigation into the alleged mis-selling of foreign exchange derivatives to corporate clients in Spain, people familiar with the matter told the Financial Times.

Germany’s largest bank on Tuesday informed staff that Louise Kitchen, head of Deutsche’s asset wind-down unit, and Jonathan Tinker, co-head of global foreign exchange, were both stepping down and would leave the bank.

The departures were announced in memos to staff seen by the Financial Times and first reported by Bloomberg. Deutsche Bank did not give reasons for the departures, two of several senior management changes announced on Tuesday.

People familiar with the details told the Financial Times that the resignations of Kitchen and Tinker, who have both worked at Deutsche Bank for more than 15 years, were linked to Project Teal — an internal investigation into alleged mis-selling of foreign exchange derivatives that pushed some small companies in Spain into financial distress and led to a series of out-of-court settlements.

The probe is one of several compliance issues overshadowing the tenure of chief executive Christian Sewing, who has been in charge of Deutsche Bank since April 2018 and has promised to improve the lender’s internal control mechanisms.

However, German financial watchdog BaFin in April ordered Deutsche Bank to fix its anti-money laundering safeguards at the same time as it broadened and extended the mandate of a special representative parachuted in to the bank in 2018 to monitor the lender’s progress on tightening its internal controls. Deutsche said at the time it had “significantly improved” its controls.

In March, Deutsche chief legal officer Stefan Simon was put in charge of the anti-financial crime unit and compliance — areas that had previously been overseen by chief risk officer Stuart Lewis, who will leave the bank in 2022. The lender has subsequently appointed a new global head of anti-financial crime.

The FT revealed in January that Deutsche was investigating whether its staff had mis-sold sophisticated investment banking products to clients in breach of EU rules and then colluded with individuals within these companies to share the profits.

Two employees who were operationally in charge of the potentially problematic activities have already left the bank. Now two executives who oversaw the business unit where the sales happened are leaving too. Süddeutsche Zeitung wrote about the link between Project Teal and the departures first.

Deutsche Bank declined to comment.

“We thank [Kitchen] for her contribution to the rapid establishment and success of the [Capital Release Group] in helping to transform our bank, and for her work over more than 15 years in senior positions across the bank’s trading platforms and covering corporate and institutional clients,” Deutsche’s chief transformation officer Rebecca Short wrote in a memo to staff.

Ram Nayak, Deutsche’s global head of fixed income, said in a separate email that Tinker “has played an important role in the development of our FX business, and I would like to thank him for his contribution to the franchise”.

Kitchen and Tinker did not respond to FT requests for comment.

The Project Teal probe was triggered by client complaints and found that Deutsche had wrongly categorised client firms under Mifid rules — the Markets in Financial Instruments Directive.

These require banks to separate clients by levels of financial sophistication, such as retail investor, professional investor or counterparty, meaning another bank or financial institution.

Deutsche believes some of its staff knowingly sold inappropriate or unsuitable products to customers who may not have been able to understand and shoulder the risk they were taking with these positions, people familiar with the probe said. The lender is not looking at just a few isolated cases but at what appears to be a broader pattern of misconduct over several years,

One of them said that the topic was “toxic” for Deutsche Bank.

Earlier this year, the lender said that it had “initiated an investigation in relation to our engagement with a limited number of clients”, adding that it could not comment on details as the probe was continuing.