Spy chief defends ban on Chinese tech giant Huawei

The chief of Australia's secretive electronic spy agency has given an insight into why Chinese tech giant Huawei was banned from supplying equipment to Australia's emerging 5G mobile network.

In rare public comments, the head of the Australian Signals Directorate, Mike Burgess, told Canberra's national security community he advised the government to exclude "high risk vendors" because a "potential threat anywhere in the network is a threat to the whole network".

In the dying hours of the Turnbull prime ministership, Huawei and another Chinese firm, ZTE, were without fanfare blocked from bidding to supply components the new next generation network.

Explaining the background to the decision, and without mentioning China, Mr Burgess said his agency cares "about the threats posed by people outside Australia".

"The stakes could not be higher," Mr Burgess said.

"This is about more than just protecting the confidentiality of our information. It is also about integrity.

"Getting security right for critical infrastructure is paramount.

"The potential threat of anywhere in the network is a threat to the whole network.

"My advice was exclude high risk vendors from the entirety of the networks."

He said the decision wasn't take lightly and was backed by the agency's technical advice.

"We will need to be open-eyed on the potential threats that any significant change of this kind poses to Australia's important interests," he said.

Asked about the decision this morning, Prime Minister Scott Morrison said the decision didn't risk Australia's relationship with China, our biggest trading partner.