"We initiated an investigation in relation to our engagement with a limited number of clients," a bank spokesman said in a statement on Sunday, following a Financial Times report on the investigation. Deutsche bank won’t comment further until it completes the review, he said.

The probe, codenamed Project Teal, was started in response to client complaints last year and originally focused on a desk in Spain that sells hedges, swaps and derivatives, a person familiar with the matter said. It appears that only Spain and Portugal-based clients were affected, the person said.

The investigation comes as Chief Executive Officer Christian Sewing seeks to improve relations with regulators and draw a line under a string of previous missteps. Deutsche Bank paid billions of dollars in fines and settlements in recent years for misconduct ranging from failure to stop money laundering to selling toxic mortgage securities and rigging benchmark interest rates.

The latest probe seeks to determine whether clients were incorrectly sorted according to their financial sophistication under the Markets in Financial Instruments Directive, and whether the bank’s staff sold investment banking products to clients in breach of the EU rules, the person said.

The probe has been expanded across Europe, and the bank is also looking at whether employees colluded with staff at some of the clients to split the profits, the FT reported.

The misconduct appears to be broad-based over several years, rather than an isolated occurrence, the FT said in its report. It is centered around a former employee who has already left the bank, according to the newspaper.