The complaints reportedly came from current and former members of staff, the report, which did not quote sources by name, said.

Citigroup has appointed law firm Paul Weiss to investigate complaints about the conduct of Andy Sieg, the US bank's wealth-management chief, Bloomberg reported yesterday, citing “ people with direct knowledge of the matter.” The newswire did not identify its sources by name.

Family Wealth Report contacted Citigroup for comment; it did not respond at the time of going to press. This publication may update in due course.

Sieg has drawn complaints from existing and former staff accusing him of intimidating and unfairly sidelining employees since he arrived almost two years ago, including allegations of expletive-filled rants and sarcastic comments, the Bloomberg report said. 

Paul Weiss has completed its investigation. More than a dozen people have been interviewed, including some as recently as July. The report said that Citigroup declined to comment on the outcome of the probe.

Sieg runs the global division and also sits on the bank’s 18-person executive management team.

Bloomberg said the law firm’s inquiry was opened after a request from human-resources chief Sara Wechter. The bank’s board, led by chair John Dugan, also received anonymous complaints critical of Sieg’s conduct at Citigroup and during earlier periods of his career, the report said, citing correspondence it has seen.