Three men have been charged with Harris' murder and two are behind bars - Nicky Bryan Dodd, 41, from Raumanga, appeared in Whangarei District Court last week and another man was already in custody on unrelated matters.
The third man is Walter Reid Ngaau, who is actively evading the police.
Police appealed for Ngaau to come forward last week and issued a warning to those helping him avoid arrest.
"We want to remind anyone who may be assisting Walter to evade police that this is a criminal offence and we will be taking this type of behaviour very seriously," said Detective Inspector Dene Begbie.
"Police have been working tirelessly on this investigation since October and have made a number of enquiries to locate Walter however these have been unsuccessful.
"Walter should not be approached. If you know where he is, or he is sighted then please call 111 immediately."
Ngaau has connections in Northland and Auckland - where police are hunting another suspected killer.
Last week Auckland mother-of-two Chozyn Koroheke was gunned down at a house in Pakuranga Heights.
Police say her partner, Turiarangi Tai, is a "person of interest" and have been on the hunt for him for more than a week.
Tai has nine warrants out of his arrest for unrelated matters including unlawfully taking a motor vehicle, dangerous driving, wilful damage and failing to stop for police.
The 22-year-old is known to police and has a violent past.
In 2012, when he was 18, Tai pleaded guilty to a charge of injuring with intent to injure in the Tauranga District Court after he attacked a man who refused to share a cigarette.
The man was beaten about the head and reportedly lost consciousness before later waking in hospital.
Police investigating Horokeke's death, believed to be a family violence-related incident, have also issued a warning to Tai's associates who are likely helping the tattooed fugitive lay low.
"We would like to warn the people assisting [Tai] that they are committing a criminal offence, which police treat very seriously, and they're liable to be charged with an offence themselves," said Detective Senior Sergeant Kevin Tiernan.
"Someone out there will know where he is and we would appeal to those people to do the right thing, not only for [Tai], but also for Chozyn and her family, and to call the police."
Tai's mother appeared in a police video on Tuesday pleading for her boy to come forward. "We love you, we miss you, we want to keep you safe," said the woman, named only as Susan.
"I know whatever you're going through, but if you need my help I'll be with you every step of the way, and if you need me to come with you to go into the police station I'll come with you."
"I need you to come forward just to sort this out," Susan pleaded.
"Please hun, we need you to come forward. All the family miss you, we love you and want to keep you safe, and we just want to get through this."