An 'unprecedented' cyber attack against the Nine Network has shut down parts of the company

The Nine Network has been the target of one of the largest cyber attacks on a media company in Australia's history. It's the first time Nine has been unable to air a TV program because of an external threat.

Nine was unable to broadcast its Weekend Today program on Sunday, initially thought to be because of severe technical issues. Many aspects of their television and digital production systems are still offline, but the Today show is back on air.

Nine said it does not know who is responsible for the attack.

Employees at Nine have been instructed to work from home until further notice, as the company continues to resolve the issue. The company said emails did not appear to be impacted but the Nine IT network - including the tools that allow them to produce live TV - had been affected.

Nine Entertainment also owns The Sydney Morning Herald, The Age and The Australian Fin­ancial Review - and some systems used by those outlets have also been affected.

Some services on Government-issued phones and tablets were also disrupted - however, it is not clear if there is any link between what happened at Parliament House and Nine.

Both Nine and the Department of Parliamentary Services are working with the Australian Cyber Security Centre to resolve the issue - however, Nine reports it could take "weeks" to fully recover.