BlackRock and Commerzbank Have This Duo to Thank for Tax Raids

BlackRock Inc. and Commerzbank AG have both had their offices raided in the last two years by German prosecutors seeking evidence in a sweeping probe into so-called Cum-Ex dividend trades. Turns out authorities were tipped off by two men now standing trial in what’s been labeled the country’s biggest-ever tax heist.

Martin Shields and Nick Diable, two former investment bankers appearing in Bonn over the controversial tax strategy, gave prosecutors key information about how the complex deals were set up and who participated, an officer of a special police unit investigating Cum-Ex told the court. The information provided by the ...