Australia's weather bureau has refused to comment on a media report that it has been hacked in a major cyberattack that compromised sensitive systems across the federal government.

Australian Broadcasting Corp. reported on Wednesday that China has been blamed for the recent attack that breached the defenses of the Bureau of Meteorology's computers and would costs millions of dollars to fix.

The bureau said in a statement it does not comment on security matters.

The statement says: "The bureau's systems are fully operational and the bureau continues to provide reliable, on-going access to high quality weather, climate, water and oceans information to its stakeholders."

The ABC report, citing unnamed officials, said the motivation for the attack could be commercial, strategic or both.