A cyber attack has disrupted Channel Nine's live broadcasts from Sydney, the TV company has confirmed, at the same time as an attack led to Parliament House's email system being taken offline.

As a result of the attack, the channel's Sunday morning news programme, Weekend Today, was not aired, nor was its 5pm news show, although future programming is expected to transmit as normal.

Although the nature of the attack has not yet been confirmed, Channel Nine said it was investigating whether it was a matter of "criminal sabotage of the work of a foreign nation".

At the same time, the country's assistant minister for defence Andrew Hastie told News.com.au that the government was forced to cut access to IT and emails at Parliament House to protect against a cyber attack related to an external provider.

"This is a timely reminder that Australians cannot be complacent about their cyber security," Mr Hastie said.

"Cyber security is a team effort and a shared responsibility. It is vital that Australian businesses and organisations are alert to this threat and take the necessary steps to ensure our digital sovereignty."

Nine Entertainment, the broadcaster's parent company, which also owns the Sydney Morning Herald and The Age newspapers, confirmed that it had been targeted by an attack, but it is unclear whether the incidents are linked.

In its statement Channel Nine said: "A cyber attack on our systems has disrupted live broadcasts today however, we have put processes in place to ensure we’re able to resume our normal broadcast schedule."

Last June, the country's prime minister Scott Morrison claimed that Australia was the target of a "sophisticated" cyber attack from an unnamed foreign state.

At the time, Mr Morrison said the attacks targeted all levels of the government - as well as political organisations, essential service providers and operators of other critical infrastructure.