Employees of Melbourne’s fire brigade accessed email accounts of senior executives and passed on sensitive information about potential investigations into union boss Peter Marshall after he asked them to go snooping, Victoria’s anti-corruption watchdog has found.

The Independent Broad-based Anti-corruption Commission found the state firefighters union had “unprecedented” influence and control over the Metropolitan Fire Brigade and that it had found five incidents of information being accessed or disclosed without authorisation in 2018 and 2019.