Giving evidence on Thursday, Police Commissioner Grant Stevens offered details of the only investigation conducted so far using the unexplained wealth provisions which were first enacted in SA in 2010.

The inquiry, into the target known as T2, began in 2013 and was completed in 2018, running up a bill of $2.4 million in wages and associated costs.

However, Mr Stevens told state parliament's crime and public integrity committee that in 2019, the crown solicitor decided not to refer the matter to the director of public prosecutions for further action.

"It was considered that the application would not be in the public interest based on the size and complexity of the case, the prospects of recovering money for the state if successful, and the likely impact on public resources," the commissioner said.

Mr Stevens said police would be reluctant to conduct another such investigation because of the complexities and limitations of the current legislation.

He said those limitations were "such an impediment that the intended benefit could not be achieved".

"SAPOL would be extremely hesitant to initiate a new unexplained wealth investigation in the current legislative environment given experiences during the T2 investigation," the commissioner said.

"The T2 investigation alone involved a full-time commitment of three sworn officers and 2.5 forensic accountants for a period in excess of six years.

"SAPOL expended in excess of $2.4 million on that single investigation for no result."

In response to questions, Mr Stevens suggested police would welcome changes to the legislation which would grant powers similar to those available in NSW, where those under investigation could be compelled to answer questions about their wealth.

"That would certainly provide some momentum in the process," he said.

Australian Associated Press