By Lewis Jackson

SYDNEY (Reuters) -The Australian Treasury has referred a confidential document leak scandal involving professional services firm PricewaterhouseCoopers (PwC) to police, Secretary to the Treasury Steven Kennedy said on Wednesday.

The government, a PwC Australia client, has accused the firm of using confidential information about new anti-tax avoidance measures to win more business, in what it has called a major breach of trust.

PwC Australia's CEO stepped down this month and the firm has said it is "committed to learning for our mistakes".

The firm's former head of international tax, Peter Collins, improperly used confidential Commonwealth information, and emails tabled in parliament earlier this month revealed "a wide range of individuals" at the firm were privy to the information, said Kennedy.

"In light of these recent revelations and the seriousness of this misconduct, the Treasury has referred the matter to the Australian Federal Police to consider commencement of a criminal investigation," he said.

The Australian Federal Police is investigating the alleged misuse of confidential government information, a spokesperson said in a statement to Reuters.

PwC Australia will continue to cooperate fully with any investigations into this matter, a spokesperson said.

PwC said this month that former Telstra and Optus CEO Ziggy Switkowski will lead an independent review into the leak and will report his findings and recommendations in September.

Amid calls to ban the firm from government work, Treasurer Jim Chalmers on Monday foreshadowed steps to crack down on similar behaviour but declined to provide specifics.

Australian Senators Deborah O'Neill and Andrew Bragg plan to raise the issue and demand more information during scheduled parliamentary hearings next week, spokespeople told Reuters.

(Reporting by Lewis Jackson, Additional reporting by Chandni Shah; editing by Louise Heavens and Jason Neely)