Greens SA senator Barbara Pocock has formally referred the matter to the National Anti-Corruption Commission, which is independent and has the authority to compel witnesses.

PwC staff shared confidential Treasury information on planned new tax rules – to stop multinationals from lowering their tax bill by shifting profits from Australia to other jurisdictions – with other PwC staff and some clients.

Treasury referred the leak to Australian Federal Police for investigation. In June, PwC gave a Senate committee the names of partners who had received the confidential Treasury information.

Last week, the firm announced a new CEO had been drafted and had agreed to divest its state and federal government consultancy business to a private equity firm for $1.

Pocock said there were still many unanswered questions and the anti-corruption body would have the power to uncover key details.

“The PwC tax leaks scandal has been airing in public for the past five months and so far we know too little about who was at fault, who benefited and what consequences there will be,” she said.

Pocock also said there were questions to be answered by government agencies including the role they played in uncovering the incident.

“While we welcome the AFP investigation to prosecute appropriate criminal charges, there are wider issues that need to be addressed to ensure that our systems of government are not open to corruption,” she said.

PwC received over $500m in government contacts in the past several years.

The federal anti-corruption commission became operational on July 1.

-with AAP