German law enforcement officials raided the offices of Deutsche Bank on suspicion of the fraudulent advertising of sustainable investment funds at its DWS unit, dealing yet another setback to CEO Christian Sewing’s attempts to move on from years of corruption scandals.

The investigation revolves around allegations—leveled by a former DWS manager—that the retail money management business engaged in “greenwashing,” in which environmental, social and governance (ESG) investments are sold under false claims.

Roughly 50 officials from the Frankfurt public prosecutor, German securities regulator BaFin, and the federal criminal police office BKA were deployed to the headquarters of the two financial institutions to seize evidence on Tuesday.

“The allegations are that DWS has been advertising so-called ESG financial products for sale as being particularly green and sustainable when they actually weren’t,” a spokesman for the public prosecutor told Fortune, which has been looking into the claims since January. “In the course of our investigations we’ve found evidence that could support allegations of prospectus fraud.”