Government stays mum on China hack

The government has remained tight-lipped on reports China was behind a "sophisticated" cyber attack on federal parliament earlier this year.

The Reuters news agency on Monday reported five separate sources pointing the finger at China for the pre-election attack.

The cyber attack also targeted the Liberal, National and Labor party computer systems.

Australia's cyber intelligence agency, the Australian Signals Directorate, concluded in March that China's ministry of state security was responsible for the attack, Reuters reported.

The prime minister's office and the Australian Signals Directorate, declined to comment on the report.

Labor foreign affairs spokeswoman Penny Wong said it was up to the government to decide whether it was appropriate to reveal who might be responsible for the attack.

China's foreign ministry said it opposed all forms of cyber attack and cyber theft.