Tony Negus, the Australian Federal Police commissioner, said that Australian computer owners should invest in anti-virus software.

Negus, who gave a speech at the second annual Australian High Tech Crime Conference, warned that cyber crime had become so sophisticated that users could have their computers hacked into without their knowledge.

The technology had advanced so rapidly that nowadays 2 billion people have access to computers, Facebook clocks in 8 billion hits a day, and more than 5 billion people have mobile phones.

But along with the advances came criminals working to circumvent security measures and waging a war with law enforcement. ''There is an increasing potential for ordinary people to become victims of crime... But less than 50 per cent of Australians even have anti-virus software," Negus said.

He adds that older people have to familiarize themselves with the problems of cyber crime, which is an issue that did not exist when they were growing up.

''Many people in this room started out using manual typewriters... Today most new employees will never have known a world without mobile phones," Negus said.

A global taskforce had been established to work out modes of collaboration and partnership. The taskforce includes the Australian Federal Police and representatives of the United States and Britain.