The Australian government has asked resource companies to step up their security against cyber attacks from overseas groups.

The government has warned companies that offshore cyber-security threats were intensifying.

Australian Attorney-General Robert McClelland told Reuters, "There is no doubt that cyber-security threats are becoming worse."

"Without talking about specific incidents, there have been a number of reports concerning our resource companies," McClelland added.

In March this year, Sydney’s Daily Telegraph reported that the parliamentary computers of Australian Prime Minister Julia Gillard and those of at least two senior ministers had been reportedly subject to hacking for over a month beginning in February.

The report said that the Australian government was alerted about the breach by American intelligence officials, who believe that several thousand e-mails may have been accessed from the computers of at least 10 ministers.

The paper said that Chinese intelligence agencies were among the suspects citing government sources.

It said, "Four separate government sources confirmed that they had been told Chinese intelligence agencies were among a list of foreign hackers that are under suspicion."