Chinese hackers have stolen top-secret blueprints of Australia's new intelligence agency headquarters, a report said Tuesday, but Foreign Minister Bob Carr insisted ties with Beijing would not be hurt.
The Australian Broadcasting Corporation said the documents taken in the cyber hit included cable layouts for the huge building's security and communications systems, its floor plan and its server locations.
Carr said the government was "very alive" to the threat of cyber attacks on national security, adding that "nothing that is being speculated about takes us by surprise".
But he refused to confirm or deny any cyber attack, or whether China was behind one, saying he wouldn't comment "on whether the Chinese have done what is being alleged or not."
"I won't comment on matters of intelligence and security for the obvious reason: we don't want to share with the world and potential aggressors what we know about what they might be doing, and how they might be doing it."
For its part, China noted that it was "very difficult to find the origin of hacker attacks", with foreign ministry spokesman Hong Lei questioning "where the evidence is for the relevant media to make such reports."
"China pays high attention to the cyber security issue and is firmly opposed to all forms of hacker attacks," Hong told reporters in Beijing.
"Since the cyber security issue is a problem faced by the whole world, so we should have an even-tempered discussion on this issue and make joint efforts to maintain a peaceful, secure, open and cooperative cyberspace.
"Groundless accusations will not help solve this issue."
While Australia has a longstanding military alliance with the United States, which has traded accusations with Beijing over cyber espionage, China is its key trade partner and the two countries have been forging closer ties.
Carr insisted that the relationship would not be damaged by the allegations, which follow several other hacking attacks on government facilities in the past two years.
"It's got absolutely no implications for a strategic partnership," he said. "We have enormous areas of cooperation with China."
Opposition politicians called for an independent inquiry into the "sorry saga" but Prime Minister Julia Gillard declined to comment on what she called "inaccurate" and "unsubstantiated reports".
The state broadcaster's investigative programme "Four Corners" said the cyber attack on a contractor linked to the new Canberra headquarters of the Australian Security Intelligence Organisation was traced to a server in China.
It cited security experts as saying the theft exposed the agency to being spied on, and may be the reason for a cost blowout and delays to the opening of the building, which was supposed to be operational last month.
Des Ball, from the Australian National University's Strategic and Defence Studies Centre, said the blueprints would show which rooms were likely to be used for sensitive conversations, and how to put devices into the walls.
"Once you get those building plans you can start constructing your own wiring diagrams, where the linkages are through telephone connections, through wi-fi connections," he was quoted as saying by ABC.
The report, which did not say when the alleged theft took place, comes amid deepening concern about aggressive state-sponsored hacking by China.
US research company Mandiant in February claimed a Chinese army unit had stolen hundreds of terabytes of data from at least 141 organisations, mostly based in the United States.
It followed a US congressional report last year naming China as "the most threatening actor in cyberspace".
In Australia, the computers of the prime minister, foreign minister and defence minister were all suspected of being hacked in 2011 attacks reportedly originating in China.
Beijing dismissed those allegations as "groundless and made out of ulterior purposes".
Earlier this year, computer networks at the Reserve Bank of Australia were hacked, with some said to be infected by Chinese-developed malware searching for sensitive information.
In 2012 Chinese telecoms giant Huawei was barred from bidding for contracts on Australia's Aus$36 billion (US$35 billion) national broadband rollout due to fears of cyber attacks.