A scathing report into PwC Australia has blamed a “shadow” culture that tolerated bad behaviour in the pursuit of profit “growth at all costs”, and a lack of governance that “went unexamined and uncorrected for many years” that led to the firm’s tax leaks scandal.

The review, by former Telstra chief executive Ziggy Switkowski, laid bare the brutal, uncompromising culture at the top of the big four accounting firm, which had become an unaccountable boys’ club with an all-powerful CEO who could not be challenged.