ANZ Group Holdings (ASX:ANZ, NZE:ANZ) accepted all recommendations from an independent culture and risk governance review by American management consulting firm Oliver Wyman of its Global Markets business, according to a Thursday statement by the bank.

Oliver Wyman's review found a generally positive culture within the institutional and market divisions, with staff willing to raise conduct-related issues, per the statement.

However, it identified distinct sub-cultures within the business that could lead to workplace misconduct or a lack of risk awareness in decision-making, the statement added.

The review also highlighted isolated instances of misconduct within the markets division in Sydney, London, and Singapore, including bullying, aggression, and substance abuse.

Market leaders were criticized for failing to effectively address inappropriate behavior, with staff reporting threats of retaliation for raising concerns, leading to a loss of trust in leadership.

Additionally, the review noted a lack of supervision by senior leaders in the Sydney dealing room, limited interaction with offices outside Australia, New Zealand, and Singapore, and insufficient site visits.

Employee-related processes, such as remuneration and consequence management frameworks, were also found to require improvement for better efficiency.

In response to the findings, the bank said it is taking several immediate actions, including creating a new executive role group head for non-financial risk program delivery.

"While numerous staff reported to Oliver Wyman that culture and risk culture within our Institutional and Markets businesses have improved significantly over the past decade, it's clear there is more work to be done to ensure conduct and behaviour issues do not go unaddressed in the future," said ANZ Chairman Paul O'Sullivan.

Shares of the bank fell 2% in New Zealand in recent Friday trade.