HSBC Bank claims Troutman Sanders failed to investigate details in a loan transaction, allowing a now-imprisoned investment banker to steal $75 million from the bank, according to a malpractice suit filed against the law firm in Manhattan Supreme Court.

HSBC had hired Troutman to advise on a $100 million loan to Hassan Nemazee, a prominent fundraiser for Democrats. The bank claims that Robert Chanis, a partner at the time, learned of a discrepancy in the information provided by Nemazee when setting up the loan documents but didn’t properly investigate.