More than 500 mental health patients have died from suspected suicide while under care in the past four years, according to figures released to Labour by the Health and Quality Safety Commission.

More than 500 people have died in suspected suicides while in mental health care over the last four years, new figures show.

Labour says the figures, released to the party by the Health and Quality Safety Commission, show mental health services are not coping with demand.

In the four years to 2015-16, 506 patients took their life by suspected suicide. The figure rose to 535 when suspected suicides by patients who were "absent without leave", on approved leave, or inpatients were included.

"These figures indicate that 20 to 25 per cent of all our suspected suicides are outpatients who have had recent contact with Mental Health Services," Labour's health spokesman David Clark said.

READ MORE: DHB, psychiatrist fail man who took his own life while in care

The Government had underfunded health by $1.7 billion and the suicide rate was another sign the system was "no longer coping", he said.

Psychotherapist and mental health advocate Kyle Macdonald said one of the red flags of a system under pressure was when patients "end up dead".

Macdonald helped launch the Peoples Mental Health Review campaign with Action Station, which has received over 500 submissions from people with poor experiences of the country's mental health system.

"It is true that people are being discharged too early; we are hearing about that pressure for people to be discharged.

"It's also true that the bar has been increased; it's harder to get into the service."

Decisions on when to discharge a patient were being driven by resourcing rather than best practice, Macdonald said.

Community mental health services were under the same pressure with some patients reporting they had not been contacted at all after being discharged.

Ministry of Health mental health director Dr John Crawshaw said any suicide was a tragedy but the rate of suspected suicides in relation to population growth was "holding steady".

"A suicide by someone who may have been in contact with a mental health provider can indicate … that the service had been working with an individual who was already seriously unwell."

All suspected suicides by mental health service users was fully investigated by the coroner and the mental health service concerned, Crawshaw said.

Minister of Health Jonathan Coleman said there was no need for an inquiry into mental health services.

"The sector provides high quality mental health services for New Zealanders from prevention through to primary care and specialist services."

There was always more to do though, he said.

"There's increased demand for all health services, which is why we've put in an extra $568 million into health this year."

WHERE TO GET HELP

Lifeline (open 24/7) - 0800 543 354

Depression Helpline (open 24/7) - 0800 111 757

Healthline (open 24/7) - 0800 611 116

Samaritans (open 24/7) - 0800 726 666

Suicide Crisis Helpline (open 24/7) - 0508 828 865 (0508 TAUTOKO). This is a service for people who may be thinking about suicide, or those who are concerned about family or friends.

Youthline (open 24/7) - 0800 376 633. You can also text 234 for free between 8am and midnight, or email talk@youthline.co.nz

0800 WHATSUP children's helpline - phone 0800 9428 787 between 1pm and 10pm on weekdays and from 3pm to 10pm on weekends. Online chat is available from 7pm to 10pm every day.

Kidsline (open 24/7) - 0800 543 754. This service is for children aged 5 to 18. Those who ring between 4pm and 9pm on weekdays will speak to a Kidsline buddy. These are specially trained teenage telephone counsellors.

Your local Rural Support Trust - 0800 787 254 (0800 RURAL HELP)

Alcohol Drug Helpline (open 24/7) - 0800 787 797. You can also text 8691 for free.

For further information, contact the Mental Health Foundation's free Resource and Information Service (09 623 4812).