Whanganui police are seeking information about two vehicles as they continue their investigation into the death of Kevin "Kastro" Ratana.
Ratana, a Mongrel Mob member, was shot at a Puriri St property on August 21 and died at the scene.
Detective Senior Sergeant Phil Skoglund said inquiries were ongoing.
"We continue to make progress and thank those who have provided valuable information to the investigation team," Skoglund said.
"Police are seeking information relating to the movements of a white Hyundai coupe which was located burned out in Seafront Rd on the evening of August 21. Police are also seeking information relating to the movements of a 1998 Blue Holden VT Commodore with spoiler and tow bar which was seen travelling at speed from the scene of the homicide.
"We know there are people in the community who have information that have not yet spoken with police. We believe they are likely to have critical information relating to Kevin's death and urge them - for the sake of Kevin's whānau - to come forward and speak to us."
To date, three men and a woman have been arrested in relation to the investigation. They face a number of charges including threatening to kill and accessory after the fact.
Nine more males have been arrested for participation in an organised crime group. Three of them have also been charged with firearms-related offences.
Information can be provided, anonymously if necessary, via Crimestoppers on 0800 555 111.