The police watchdog isn't able to investigate every case that comes across its desk because of a squeeze on resources.
The Independent Police Conduct Authority's (IPCA) group operations manager Warren Young says while the agency's financial position is sustainable, if it had more money it would be able to do more.
"It's not putting investigations into jeopardy, we tailor what we do according to the resources we have available like any agency does," he told reporters after appearing before Parliament's law and order select committee today.
"There have been cases we have not independently investigated because it's been beyond our resource."
Mr Young said a range of cases the IPCA might have investigated, including some complaints about excessive use of force, have been referred back to police.
But he said the most critical and significant complaints are always independently investigated.
Justice Minister Amy Adams, who is the minister responsible for the IPCA, said the agency is adequately funded for what it does.
She told reporters while there has been an increase in low severity cases, the most expensive cases are tracking down.
The IPCA hasn't asked at this stage for a funding boost, Ms Adams said.