The Australian Institute of Criminology study says the industry has increased by more than 40per cent in 10 years. The largest growth has been in the number of security consultants, debt collectors, locksmiths and armoured car escorts.

The rate of increase far outweighs those of the state and federal police forces, which have grown by less than 15 per cent in the same period.

The report, primarily based on the 2006 census, says the number of people working in the private security sector has grown to more than 52,700.

At the same time, people listing their profession as sworn police officer was nearly 44,900.

Despite the increasing numbers, the ratio of private security workers is only about 30per cent of the level in South Africa. And while there has been significant growth in the industry between 1996 and 2006, the authors say there is large room for growth.

''Research indicates that only around 45per cent of Australian households have basic security measures in place, suggesting considerable scope for a greater contribution from the industry to domestic crime prevention,'' the study says.

The authors of the report say that despite the rise of the private security industry, more than three-quarters of guards are earning less than $1000 a week.

By contrast about two-thirds of sworn police reported earning between $1000 and $1600 a week.

The report also notes those in private security are likely to have completed less education than those within the police force.

Census figures indicate 31per cent of private security workers did not complete high school, while the majority of police had achieved qualifications greater than a certificate four.

The report also recommends a need for further assessment on the security industry to help guide policy on accountability.