Police could be given the power to lock suspects in cells before they have been charged with a crime in a move the State Government claims will help put more officers back on the beat.
Criminal lawyers have attacked the proposal as retrograde, claiming it would result in innocent people being treated like criminals.
Under the Criminal Investigation Act, police are required to hold suspects in an office environment where they do not feel confined and an officer must supervise them at all times.
Amendments to the Act - introduced into State Parliament yesterday - would allow police to keep a suspect locked in a cell for up to 24 hours without charges being laid.
Police Minister Lisa Harvey claimed 46,000 police man-hours were wasted every year "babysitting" suspects - time that could be better spent on frontline duties.
"This is equivalent to approximately 24 police officers a year who are not available to perform frontline police tasking duties because they are required to personally guard arrested suspects for what can be protracted periods of time," she said. "Police officers were recently asked for their views on what changes could be made to reduce red tape and this was something that stood out."
The WA Police Union supports the move and claimed office environments were not always an appropriate place to hold potentially dangerous people.
Union president George Tilbury said that under the proposed changes, officers would still have the discretion to hold those not considered a threat outside of cells.
"The current situation is very resource intensive and wastes valuable police resources," he said.
Australian Lawyers Alliance president Tom Percy said it was an attack on a person's basic right to the presumption of innocence.
"Being put in a cell before you are convicted is one thing, but being put in a cell before you are even charged is a step too far," Mr Percy said.
"I think that really is a very retrograde step in terms of where we like to see ourselves as a civilised society."
The welfare of people with mental health issues and indigenous people was also identified as a concern.