Police say they have spoken to the man they believe killed a road worker in the central North Island and think others may be involved in covering up the crime.
On Friday, police confirmed that they have identified the suspect after finding a blue Jeep Cherokee they say is connected to the killing on 19 March.
George Taiaroa, 67, was shot dead on Tram Road in the Kinleith Forest while manning a stop-go sign at a single-lane bridge near Atiamuri, south of Tokoroa.
Detective Inspector Tim Anderson told Radio New Zealand's Checkpoint programme on Friday that police know where their main suspect is and have interviewed him.
Mr Anderson said the man is not known to the Taiaroa family, but a motive for the killing is becoming clearer.
He believed others may have helped the man to commit the crime or helped him try to cover it up, and is urging them to come forward.
However, he would not speculate on how close police are to arresting the man.
"We're extremely patient. In these sort of investigations they're complex. We've amassed in four weeks a significant amount of information. We have some of the best detectives across the North Island on this case - and we never give up."
The blue Jeep Cherokee that police believe was involved has been seized from a property in the Bay of Plenty and is being forensically examined.
Tim Anderson would not say when the vehicle was found, the circumstances in which it was located, or the nature the forensic tests.
Police still want to hear from people who may have seen the jeep around Benneydale, Taumaranui, Taranaki, Stratford and Rotorua.