The attack on the political parties gave the hackers access to private email correspondence between politicians,public servants,staff and other citizens,two sources told Reuters.
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House of Representatives Speaker Tony Smith and Senate President Scott Ryan said in a joint statement at the time there was"no evidence that any data has been accessed or taken at this time,however,this will remain subject to ongoing investigation".
Mr Smith and Senator Ryan said out of an"abundance of caution",user passwords had been reset.
China's Foreign Ministry has continued to deny any involvement in the cyber attack.
"When investigating and determining the nature of online incidents,there must be full proof of the facts,otherwise it's just creating rumours and smearing others,pinning labels on people indiscriminately,"the ministry said in a statement sent to Reuters.
"China hopes that Australia can meet China halfway,and do more to benefit mutual trust and co-operation between the two countries."