Police want to identify a number of possible witnesses to a stabbing in Taranaki Street in central Wellington on 28 July.
A 48-year-old man was seriously injured in the stabbing, which occurred at around 8.50pm outside the Wesley Methodist Church at 75 Taranaki Street.
The victim was provided with live-saving emergency first aid by a passer-by until ambulance and police officers arrived at the scene.
He later required emergency surgery.
Detective Sergeant Olivia Meares said: "This appears to have been a violent, unprovoked attack by an unknown offender and could well have been fatal if not for the quick response of members of the public and emergency services."
She said CCTV footage indicated that several potential witnesses have not yet spoken to the police.
Police have previously sought information about the occupants of a white van parked in the Wesley Methodist Church carpark.
"We have now established that two people got out of the van and went over to the area where the victim was stabbed. They then returned to their van and left the area," Detective Sergeant Meares said.
The van was either white or light grey and appeared similar to an older-style Mitsubishi L300 model.
Police also wanted to identify a man with long hair, which may be braided. He walked past the area around the time the victim was stabbed.
Another man wearing shorts or rolled up black pants, with a grey stripe, was also in the area at the time and police would like to speak to him.
"We believe these people may have witnessed the attack on the victim, or have information which could assist us in identifying the offender."
Anybody with information could contact police via the 105 phone service referring to Operation Wesley, file number 220729/2490.