Australian Prime Minister Julia Gillard's parliamentary computer and those of at least two senior ministers are suspected of being hacked, according to a newspaper report.
The government was alerted to the security breach by a US intelligence tip-off, Sydney's Daily Telegraph said.
It is reported that several thousand emails may have been accessed from the computers of at least 10 ministers.
The Australian authorities have refused to confirm or deny on the reports.
The cyber attacks are believed to have targeted the Australian Parliament House email network, the less secure of two networks used by MPs.
Among the computers allegedly breached were those belonging to Foreign Minister Kevin Rudd and Defence Minister Stephen Smith.
Reports suggest the hackers may have been trying to access information on Australia's lucrative mining industry.More...