Westpac allegedly played down warnings of fraud and other crimes in mortgage broking subsidiary RAMS Home Loans for more than a year, with the audit and risk executive who raised concerns claiming she was bullied by other senior managers who labelled her a troublemaker.

Samantha Aitken, the bank’s head of risk and treasury audit, is suing her employer in the Federal Court, alleging she was sidelined and prevented her from raising her concerns with regulators in 2022 and 2023.