By David Winning

SYDNEY--Westpac Banking Corp. said millions of breaches of anti-money-laundering finance laws were caused by technology shortcomings and human mistakes, but an internal investigation had not found intentional wrongdoing by any of its staff.

Westpac has been accused by Australia's financial-intelligence agency of the biggest breach of the country's money-laundering and terrorism financing laws in history, with more than 23 million breaches that include failing to detect transfers that may have been used to facilitate child exploitation in Asia and failing to report in a timely way about $7.5 billion in international transfers.

On Thursday, Westpac laid out the results of its investigation into those compliance issues, which last year led to the departure of the company's chief executive, Brian Hartzer, and resulted in Chairman Lindsay Maxsted taking early retirement.

"We completely accept that some important aspects of Westpac's financial crime risk culture were immature and reactive, and we failed to build sufficient capacity and experience in some important areas," said Peter King, who became Westpac's chief executive in April.

Westpac said it had identified three main causes of the compliance failures. Some areas of money laundering and counter-terrorism financing risk weren't sufficiently understood within the company, Westpac said. There were also "unclear end-to-end accountabilities for managing AML/CTF compliance and there was a lack of sufficient AML/CTF expertise and resourcing," it added.

The investigation also concluded that directors could have recognized earlier the systemic nature of some of the financial-crime issues that Westpac was facing. A total of 38 employees have taken a hit to their pay, including bonuses being withheld. Some staff have been disciplined, Westpac said.

Westpac is implementing the recommendations of the report, and said it is well advanced in strengthening management of non-financial risk.

"We have established a new board legal, regulatory & compliance sub-committee, appointed a deeply experienced executive to a new executive position directly responsible for financial-crime compliance, and made a number of other organizational changes," Chairman John McFarlane said.

Westpac said it is continuing to engage with the Australian Transaction Reports and Analysis Centre, or Austrac, on a lawsuit arising from the compliance breaches, and submitted its defense on May 15. 



  Write to David Winning at david.winning@wsj.com