The Albanese government is sitting on a secret report into how cyber security issues are dealt with by departments and agencies.
The report was commissioned by the prime minister's office in October in the wake of the Optus and Medibank hacks, both of which had an impact on around 10 million customers.
A Senate estimates hearing was told on Monday the review by former top bureaucrat Mike Mrdak cost just over $17,000 and a report was received on November 29.
However, the report has not been made public.
The Senate committee was told the report was commissioned to look at "how cyber issues were structured and dealt with" within the public service.
Asked by Liberal senator Simon Birmingham to table the report, cabinet minister Penny Wong said she would seek advice on it.
"The report is intended for the prime minister, for the discussion of government," Department of Prime Minister and Cabinet deputy secretary Katrina Cooper said.
"We may not be able to table it."
She said while it was common practice for such reviews to occur, they are not normally publicly released.
Ms Cooper said one of the things that came to light from the review was "a wide range of agencies had relevant responsibilities" for cyber security.
The review was needed because the issue cut across technical, legal, operational and policy aspects of government, she said.
Senator Birmingham queried why such a review was needed when the government had appointed a standalone cyber security minister, Clare O'Neil.
"Ms O'Neil is the policy lead, but this is an issue that cuts across all departments," Senator Wong said.
