A “sophisticated state actor” was behind a cyberattack on the Australian parliament’s computing network, the country’s prime minister has said.

Scott Morrison did not identify the state behind what he described as a “malicious intrusion”, that also affected the network of major political parties, on February 8.

A joint statement from House of Representatives speaker Tony Smith and Senate president Scott Ryan said at the time there was no evidence that data had been accessed in the breach, but lawmakers were advised to change passwords.

Mr Morrison revealed on Monday that the computer networks of the government parties — the Liberal Party and the Nationals — as well as the opposition Labour Party had also been affected.

Australia’s security agencies were securing those systems and protecting users, he said.

Our cyber experts believe that a sophisticated state actor is responsible for this malicious activity

“Our cyber experts believe that a sophisticated state actor is responsible for this malicious activity,” Mr Morrison told reporters.

“Let me be clear, though — there is no evidence of any electoral interference. We have put in place a number of measures to ensure the integrity of our electoral system,” he added.

The Australian Cyber Security Centre, the government’s main cyber security agency, had briefed federal and state election authorities, Mr Morrison said.

New South Wales, Australia’s most populous state, will hold elections on March 23. A federal election will be held on a date to be set in May.

Although Australian officials have not blamed any country, in 2011 it was reported that China was suspected of accessing the email system used by lawmakers and parliamentary staff.

Election interference has been high on the international agenda ever since America’s 2016 presidential vote.

Russian hackers stole and published more than 150,000 emails from various Democratic targets in what US spymasters and senior lawmakers described as a wide-ranging effort to help elect Donald Trump.