The sister of a health care worker murdered in New Zealand is pleading for witnesses to come forward as police make "strong progress" in finding the killer.
A homicide investigation was launched in Taranaki after police discovered Adrian Humphreys' body at a Tāngarākau campground on May 7.
The 57-year-old anaesthetic technician, originally from the UK, worked at Southern Cross Healthcare in Rotorua. His sister, Taresa, travelled from the UK to NZ following his murder.
Police are yet to say how Humphreys died, but continue to search for items of interest in the investigation, stating they now have a clear understanding of what took place.
"Locals will have noticed that the Police National Dive Squad and specialist search teams have been in the area recently," Detective Senior Sergeant Gerard Bouterey said.
"And while I can’t disclose what they were tasked with searching for, what I can say is we are making strong progress and we now have a clear understanding of what occurred."
The police believe those involved in his death have told others about what happened.
"This is a large burden to bear, and we encourage those holding this information to come forward and speak with us," Det Snr Srg Bouterey said.
He said police continue to update Humphreys' family on the progress and his sister has now returned home to the UK.
"His family are seeking justice and want those responsible held to account," Det Snr Srg Bouterey said.
"We hope to be able to advise them soon that we are at that stage."
Taresa is pleading for anyone with information to come forward so Humphreys can have justice after a "horrendous act".
"Adrian was a very special brother and son who embraced life to the full in all that he did," she said in a statement. "He was a very kind and caring person who would always put others first."
"This has been a very distressing and difficult time for the family not knowing who did this and why this awful act occurred to Adrian in such a remote and we thought safe country.
"We as a family reach out to those in New Zealand, who may know or who may have seen something, no matter how small, leading up to this horrendous act which took the life of my brother and my parents’ son.
"We beg you to come forward and contact the Police as a matter of urgency, so that other families do not go through what we have.
"Hopefully preventing this from happening again and that Adrian did not die in vain without getting justice."
Anyone who can help with the investigation is asked to call the dedicated phone number for this case, 0800 287 453.
