Constable William Eagle said during evidence members of the public did chest compressions but he did not respond.
Murtagh was found with a lighter and two deodorant cans. An ambulance arrived 10 minutes later.
Police recognised Murtagh, who was known to "huff" aerosols and had alcohol and drug problems, Eagle said.
Murtagh was taken to hospital where he had a cardiac arrest. He was then discharged from hospital and put into the care of hospice at his mother's house where he died on June 3.
Sergeant Tere Rei gave evidence that Murtagh had been arrested 24 times between May 2015 and May 2016.
He was charged with various offences including dishonesty crimes, offensive behaviour, breaching bail and failing to appear in court.
Lakes District Health Board mental health clinical director Dr Darren Malone who said his team assessed Murtagh but it was deemed he didn't suffer from severe mental illnesses.
Instead specialists ruled he had drug and alcohol addictions and would have hallucinations and hear voices when he was drunk.
Despite that, Murtagh remained under the mental health services' umbrella and team members tried to help him, including a social worker who tried to get the necessary documentation required for him to be admitted into a residential facility.
This proved difficult because he couldn't get a Work and Income benefit given some banks didn't want him as a customer. He also didn't have formal identification or an IRD number.
Other stumbling blocks included a shortage of detoxification "beds", a process he had to do being admitted into a rehabilitation facility.
Malone said Murtagh was reluctant to get help and would often miss medical appointments.
"I think it is a tragic case of a death of a young man at a young age. It is a sad story to read about the difficult life this man had," Malone said.
Over a period, Murtagh was seen by mental health and addiction specialists and was a patient of treatment centre Te Utuhina Manaakitanga Trust.
Trust clinical psychologist Dr Rebecca Wirihana said it would have been helpful if they had been involved more with Murtagh's care, as they found it frustrating not being able to make direct referrals for rehabilitation.
The shortage of beds at the rehabilitation facilities was also highlighted, and evidence showed there was only funding for 15 beds in Rotorua, which had to cater for five district health boards in the Midland region.
There were only two beds nationwide - and they were in the South Island - for those being put into compulsory rehabilitation, which could have been the only way Murtagh got help.
Coroner Robb said his finding wouldn't necessarily be critical of anyone but would aim to improve the way social service and government agencies worked together to reduce the risk to others.
He adjourned proceedings until after releasing his draft findings for consideration by those involved.
