Environment Minister Tanya Plibersek says her department has a small number of PwC contracts, and has asked for “strict controls” as the tax scandal unfolds.

The consultancy firm has come under fire following revelations staff shared confidential tax information from the Treasury department.

The Australian Federal Police are investigating the leak.

Ms Plibersek said once the story broke, checking what involvement the environment department had with PwC was one of the first things she did.

“We do have a small number of small value contracts,” she told ABC radio.

“I’ve asked the secretary of the department to meet with PwC and make sure that there are strict controls around those contracts to ensure that they’re being done in an ethical way.”

Ms Plibersek took aim at the coalition for its broad use of consultants while they held power.

“They spent $21 billion on outsourcing work that could have more properly been done by public servants in my own department,” she said.

Opposition finance spokeswoman Jane Hume defended the use of consultants and rejected a link to the PwC scandal.

“The Commonwealth can’t do everything on its own,” she said.

“There will always be opportunities or necessity to appoint contracts with the big consultants or other experts in the field.”

– AAP