Police were continuing to support the family.
"We feel for his family who have been going through an extremely difficult time since his passing, and while we acknowledge this result will not bring him back, we hope it may be able to bring some form of comfort to his family and friends."
Emergency services were called to Seaside Park on Brady Rd about 4.40am on May 25 and found Tupou critically injured. Attempts to save the man were made but he died at the scene.
Tupou and his family had been living in the United States but had returned to New Zealand not long before his death. They were living in Māngere.
In a police statement, Tupou was described as "a fun-loving, hard-working young man who regularly attended church and enjoyed social occasions with his friends and family".
The homicide investigation had focused on searching for a light- or gold-coloured people mover, similar to a Honda Odyssey, that was sighted in the South Auckland area between 2am and 6am on May 25.
A relative, believed to be Tupou's sister, wrote on social media about her heartbreak in already losing one sibling and now losing her beloved brother.
"For the longest time it was just us two. Then Ma'afu came along and it was us three. But then he broke our hearts when he left us and you promised it was gonna be us two to the end ... but my heart's breaking again cause now it's just me.
"Two biggest heartbreaks of my life and they're both from you and Ma'afu. Can't bare another one so watch over mum and dad and the fams. You said you got me, so make sure I don't have another broken heart anytime soon okay?"
