“This included new rules to stop multinationals avoiding tax by shifting profits from Australia to tax and secrecy havens,” it said.

“Some of the confidential information was disclosed by Mr Collins with other PwC personnel who, in turn, disclosed to clients or potential clients of PwC.”

The practitioners’ board found Mr Collins failed to act with integrity, and terminated his tax agent registration.

“We are very concerned when tax practitioners abuse their positions of trust, or fail to act with integrity,” the board’s chair Ian Klug said.

The board also determined that PwC had failed to properly manage conflicts of interest, when this confidential law reform information was shared with partners and staff in their tax practice and ordered PwC to put processes and training in place to ensure conflicts of interest are adequately managed in future.

“We acknowledge the TPB [Tax Practioners Board] found that a partner of the firm did not comply with confidentiality agreements in relation to a consultation process with Treasury, which occurred in 2014,” a PwC spokesman said.

“We also acknowledge that PwC should have had specific conflict management procedures and policies operating at the time to prevent this occurring. In each case this failed the standards we set for PwC and we deeply regret this occurred.”

PwC was ordered to ensure that appropriate training is provided on a six-monthly basis to relevant partners and staff on complying with the code of professional conduct and PwC’s policies on conflicts of interest.

The accounting firm must also provide a compliance statement to the practitioners’ board every six months until the end of the 2024 calendar year.

The board would not say if further sanctions are being considered against other PWC staff.

“At this stage, we are unable to expand further on any current or potential related investigations that might arise in future,” a spokesman said.

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