Police in south Auckland say they are under pressure dealing with increasing numbers of people who are intoxicated, or have mental health issues.
New figures show police across the country have referred almost 1000 people with mental health and addiction issues to hospital emergency departments since 2014.
South Auckland's Middlemore Hospital was the worst affected, with numbers increasing from just 13 patients seven years ago, to 367 in 2019/2020.
Counties Manukau Police district operations manager inspector, Alison Brand, said the rise in referrals came after a change in policy in 2014, following concerns about people with mental health issues or addiction problems being held in cells.
"The policy now includes a specific provision that police are to treat intoxicated detainees with specified presentations as a medical emergency and arrange for urgent hospitalisation," she said.
"Any person that is encountered by our staff on the frontline that may be under mental duress is referred for a health assessment. This may include transporting this person to the nearest emergency department for that assessment to be carried out."
College of Emergency Nurses NZ chairperson Sandy Richardson said the figures highlighted the ongoing pressures hospital health workers faced on a daily basis, and they were struggling to cope.
"It's not just people with mental health issues, there is alcohol and drugs as well," she said.
"In the past if the police picked someone up under the influence they might have put them in a cell to sleep it off. But, especially after that recent [Allen Ball] case, they are more cautious and send them to a hospital."
Ball died in police custody in Hāwera in June 2019 after being arrested for the alleged assault of his partner.
He was found to have died after taking a toxic cocktail of codeine, tramadol and alcohol.
The three officers charged with his manslaughter were found not guilty last week.
NZ Police Association president Chris Cahill said the referral figures partly reflected changing police procedures.
"Police recognise that people with mental health problems aren't criminals and shouldn't be held in a cell," he said.
"But the problem with taking people to emergency departments is they often don't have specialist staff available. So it hasn't been as successful as we would have liked."
Cahill said the end result was that police officers often had to wait for a mental health and addictions specialist to turn up to see the patient.
He said police attended 68,000 incidents nationwide for people with mental health issues last year alone.
Mental Health Foundation chief executive Shaun Robinson said the issue was a symptom of the crisis in mental health the country was facing.
"The mental health services DHBs provide continue to be overwhelmed because there's been underinvestment for decades and we have an ageing and burnt-out workforce.
"I think the police response is better [than it used to be]. But unfortunately our police are far too often acting as an emergency mental health service."
Counties Manukau Health's clinical director of mental health and addictions said it supported the work by police to provide people with the help they need.
"It is important to recognise that not all unusual or disturbed behaviour is the result of mental illness, but can be caused by a number of factors including physical illness, intoxication or emotional distress.
"We work in close collaboration with our colleagues in the emergency department (ED) to assess and enable appropriate treatment for all those who need it, recognising that Middlemore Hospital has one of the busiest EDs in Australasia. Our clinicians work on-site and are at the ED department 24 hours, seven days per week."
Figures released by Counties Manukau Health under the Official Information Act in September last year showed its Mental Health and Addiction department had a staffing shortage of 121 positions.