SECURITY experts are alarmed that a company with links to the Chinese military is bidding to supply equipment to the national broadband network, warning that the equipment could be used to spy or launch cyber attacks on Australian governments and businesses.

The United States' National Security Agency intervened to block Huawei Technologies' bids to supply equipment to AT&T last year, threatening to withdraw government business if Huawei was chosen, The Washington Post reported.

The company also has faced opposition from Indian and British intelligence agencies and Australian security experts are voicing similar concerns as Huawei seeks a slice of the $43 billion broadband roll-out.

As the rate of cyber attacks on Australian interests intensifies, an intelligence expert at the Australian National University's Strategic and Defence Studies Centre, Desmond Ball, said he didn't want to sound alarmist ''but this is the highest order risk that I would see with regard to network vulnerability''.

Bids by Huawei ''would have to be subject to the closest scrutiny but in the end it would be the government's responsibility to reject such an involvement''.