Canberra's paramedics could be resorting to placing mental health patients on emergency detention orders so they are seen in a timely manner.
The Canberra Times reported there had been a huge increase in emergency detention orders issues by paramedics in 2018-19.
The fourfold jump was largely unexplained when questions were put to the Emergency Services Agency.
But chief psychiatrist Denise Riordan said the jump appeared to be due to "literal" interpretations of the legislation.
While the legislation is intended to take non voluntary patients to hospital if they are a threat to themselves or others, it had been used broadly across many mental health patients who were taken to hospital via ambulance.
"It doesn't say anything in the legislation about if that person is declining to seek assistance or not," Dr Riordan told annual report hearings on Monday.
She said paramedics were also motivated by a desire to get patients seen more promptly in the emergency department.
Patients brought in under the mental health act have to be seen within four hours to comply with legislation.
"I think it was incredibly well intentioned for sure." Dr Riordan said.
But the decision from paramedics had put pressure on Canberra Hospital's emergency department, she said.
Clinicians had been forced to choose between treating patients in a clinically appropriate manner or complying with the legislation.
"There may be someone in the emergency department who is there as a voluntary client who may actually be more unwell than someone who is brought in under an emergency act," she said.
"I think that what's happened is that there's been an interpretation that anybody ringing for an ambulance ... their interpretation has been that is somebody who needs to go on the act."
Asked why there was a sudden increase two years after laws gave paramedics to power to place patients on emergency orders, Dr Riordan said paramedics appeared to be acting on guidance or advice from the service.
She said the legislation may need to change.
Canberra Hospital's emergency department is often under significant strain and patients left waiting well beyond clinically recommended times.
There has also been a significant increase in mental health patients presenting to Canberra Hospital in recent years.