Deutsche Bank facilitated hundreds of millions of dollars of transactions for a corrupt Cyprus bank that served as a hub for illicit money from “the darkest corners of the criminal underworld”, a trove of secret documents obtained by BuzzFeed News reveals.

Deutsche – and its New York subsidiary under scrutiny for its loans to Donald Trump – provided a crucial bridge between FBME Bank and the global financial system, acting as its longstanding correspondent bank in the US and helping some of its most nefarious clients move illicit money into the West.

FBME was banned from using the dollar this year after losing a protracted legal battle with the US government – three years after the Financial Crimes Enforcement Network, known as FinCEN, first moved to stop the bank sending “dirty funds through the U.S. financial system”.

FinCEN kept much of its evidence against FBME secret – but the files obtained by BuzzFeed News have exposed the Cyprus bank as a major conduit for funds linked to terrorism, organised crime, and chemical weapons, and revealed how blue-chip Western institutions enabled its activities. In recent days we disclosed how FBME’s ultra-powerful international law firms – including an attorney playing a key role in the Trump-Russia investigation – crusaded for the bank while accountants at two of the world’s biggest accounting firms signed off its activities, and we exposed a network of Kremlin-linked slush funds inside FBME funnelling money to shadowy people fronting for Syria's chemical weapons programme, organised crime, and ISIS.

The revelations have prompted calls from politicians and campaigners for a crackdown on corrupt institutions in money laundering hotspots such as Cyprus – and the enablers that act as their gateway into the West. Ian Austin, a British member of parliament, said “BuzzFeed's investigation provides even more evidence of illicit funds flowing through Cyprus” and called on the UK government to act swiftly to shut “criminals and stolen money” out of the financial system. Transparency International called for a “drastic overhaul” of financial regulations to hold bankers, lawyers, and accountancy firms to account for their role in enabling corrupt banks implicated in money laundering.

Banks operating in the US are required by law to take steps to ensure that the money they channel into the American financial system is clean. The documents do not suggest Deutsche Bank knowingly facilitated illegal activity – but they raise questions about how the banking giant processed hundreds of millions of dollars connected to some of the world’s worst scourges without spotting enough cause for suspicion to sever ties with FBME.