Australia's parliament revealed Friday that its computer network had been compromised by an unspecified "security incident" and said an investigation was under way.
"Following a security incident on the parliamentary computing network, a number of measures have been implemented to protect the network and its users," parliamentary authorities said in a statement.
Officials declined to comment on the nature of the cyber security breach, but said there was no initial evidence that data had been accessed.
"We have no evidence that this is an attempt to influence the outcome of parliamentary processes or to disrupt or influence electoral or political processes," a statement said.
"Our immediate focus has been on securing the network and protecting data and users."
All parliamentary passwords were reset as a precaution.
The Australian Signals Directorate (ASD) confirmed it was working with the parliament in response to the attack, a move that indicates that sophisticated actors may be involved.
National broadcaster ABC reported intelligence agencies were looking into whether foreign governments could be behind the attack, including China.
"ASD and its Australian Cyber Security Centre will continue to work with (Parliament) to understand the full extent of this network compromise," and ASD spokesperson told AFP.
"Meanwhile, the necessary steps are being taken to mitigate the compromise and prevent any harm."