Australian officials have refused to confirm or deny a report that Chinese hackers stole blueprints for the country's new spy agency headquarters.
The Australian Broadcasting Corporation has reported that the plans for the new Australian Security Intelligence Organisation (ASIO) HQ - which allegedly included the building's cable and server layouts and security systems - had been illegally accessed by server in China, which had hacked a building contractor's system.
The programme further alleged that the Prime Minster's Office, the Defence Ministry and the Department of Foreign Affairs had been hacked, but did not identify the source of its information.
Chinese foreign ministry spokesman Hong Lei said: "China pays high attention to cybersecurity issues, and is firmly opposed to all forms of hacker attacks," according to The Guardian.
He added: "Groundless accusations will not help solve this issue."
The building, in Canberra, has so far cost 630 million Australian dollars (£401 million) from an original budget of 460 million dollars, and is nearly finished.
The Greens party - which the ruling Labour party needs to support its minority government - has called for an inquiry into the breach.
Des Ball, an Australian National University cybersecurity expert, said China could use the blueprints to bug the building.
Ball told the ABC that given the breach, ASIO would either have to operate with "utmost sensitivity" within the building or simply "rip the whole insides out and ... start again."
Foreign Minister Bob Carr did not comment directly on the claims, but said the government was "very alive" to cybersecurity threats and the allegations didn't affect relations with China - the country's biggest trading partner.
He said: "I won'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."
But he said the report had "no implications" for a strategic partnership. "We have enormous areas of co-operation with China," he said.
Earlier this year, hackers from China were thought to be behind an attack on the Reserve Bank of Australia, according to the Australian Financial Review.
Attorney General Mark Dreyfus, the minister in charge of ASIO, also refused to confirm or deny the report. He later said the building did not need to be redesigned, and that the agency will move in this year.
"This building is a very secure, state-of-the-art facility," he said, adding that the ABC report contained "unsubstantiated allegations."
"I'm not going to comment on operational matters involving the Australian Security Intelligence Organization or any security matters," he said.
Questioned about the alleged security breach in Parliament, Prime Minister Julia Gillard described the ABC report as "inaccurate" but refused to go into detail.
Calling for an inquiry into the building's future, Greens leader Christine Milne said: "It is time that we had an independent inquiry into the whole sorry history of the ASIO building and the extent to which the current hacking has compromised its capacity to ever be the building and serve the purpose for which it was intended."
Dreyfus didn't immediately respond to the Greens' call for an inquiry.