Australian government officials will be asked in a parliamentary hearing Thursday to provide more details on their pursuit of PricewaterhouseCoopers over a tax scandal, after referring the consultancy to the police for a criminal investigation.

Finance Minister Katy Gallagher is among those expected to appear at the hearing in Canberra as the government grapples with a breach of confidentiality with one of its tax policy advisers. PwC Australia’s former head of international tax, Peter Collins “improperly used confidential Commonwealth information,” secretary to the treasury Steven Kennedy said in a statement Wednesday.

PwC has been under fire amid revelations that Collins obtained secret information during his time as an adviser to the government and leaked it to his colleagues who used it to shop tax-planning advice to global corporate clients. Emails dating from 2014 to 2017, released following demands from parliament, show the extent of the collaboration between Collins and his colleagues in advising clients believed to include some of the biggest US tech firms.

Former PwC Australia Chief Executive Officer Tom Seymour and two other executives stepped down after the emails were made public and the firm announced an independent review of its governance, accountability and culture.

“We note the statement from the Treasury Secretary and will continue to cooperate fully with any investigations into this matter,” a PwC Australia spokesperson said Thursday.

Read more: PwC Australia Tax Scandal Fuels Global Implications

Clare O’Neil, minister for home affairs and cyber security, said PwC’s conduct was a “grotesque betrayal of trust” and the matter is being taken “incredibly seriously.”

“We are looking at a whole of government response to this,” she said in an interview on ABC Radio Thursday. “We will not stop until we get to the bottom of exactly what has happened here. It is a disgraceful incident and it must be properly investigated and the people responsible held to account.”

She said there are legal constraints around canceling the government’s existing contract with the consulting firm, but that “there is some furious work going on within government to what the legal constraints are on us here to make sure that we are appropriately addressing the issues that have been raised.”