German prosecutors searched Deutsche Bank's headquarters in connection with an investigation into a multibillion-dollar tax fraud scheme known as "cum-ex," Deutsche Bank said, Reuters reported.

Germany's biggest lender is one of many banks that prosecutors have searched in connection with a tax scheme that flourished more than a decade ago.

The Cologne prosecutor's office, without naming Deutsche Bank, confirmed that it conducted a search of the bank and its auditing firm in Frankfurt that involved more than 100 investigators/.

Deutsche Bank, led by CEO Christian Sewing, has been trying to clean up its reputation since he took over the bank in 2018.

In the trading scheme under investigation, known as "cum-ex," banks and investors quickly exchanged company stock on dividend day, diluting stock ownership and allowing multiple parties to falsely claim back taxes on dividends. The loophole, now closed, also developed into a political scandal, forcing German Chancellor Olaf Scholz to testify earlier this year.