Tuuholoaki was one of two men shot in the drive-by style shooting on Queen St last week.
Detective Senior Sergeant Craig Bolton said a small group of people had started fighting and then one offender pulled out a firearm and fired up to four shots.
The alleged shooter was on a Lime scooter before and after the incident.
One person was shot in the head and another in the abdomen.
One of those was Tuuholoaki. He died in hospital on Friday.
Bolton said Tuuholoaki “was taken off life support and sadly succumbed to his injuries with family beside him.
“Our thoughts are with Sione’s family as they continue to grieve their loss,” he said.
“This is a very difficult time for them, and we are ensuring they have support in place. Our investigation team are continuing to work hard to bring them answers and to ensure the person responsible is held to account.”
The other shot man remains in a stable condition at Auckland City Hospital.
Meanwhile, police are still searching for the gunman, identified as “dangerous” 24-year-old Dariush Talagi.
Bolton said there was no risk to the public but Talagi was “considered dangerous”.
Talagi had distinctive facial tattoos, Bolton said.
“Our message to Dariush would be to hand himself in, or for anyone who sees him to call us immediately,” he said.