"We are currently speaking to a number of people as part of our investigation as we work to establish all of the circumstances surrounding this incident," he said.
The young man remains in hospital in a stable condition.
Anyone with information about this incident is asked to contact Counties Manukau Police on 09 261 1321, or Crimestoppers anonymously on 0800 555 111.
The incident comes after a spate of violent crimes and firearms incidents in South Auckland in recent months.
A trail of violence and crime:
• August 24: A man died after being assaulted in the Auckland suburb of Ōtāhuhu.
• August 24: A 31-year-old man was seriously injured after being stabbed at a bar in Manukau, South Auckland.
• August 23: A home invasion in Auckland suburb of Onehunga left one person injured.
• August 9: A man suffered life-threatening injuries after a shooting at Billington Ave in Ōtara. The South Auckland property was described by neighbours as being occupied by gang members.
• July 26: A teenager was taken to hospital in a critical condition after a shooting on Featherston Cres, in Ōtara. A 34-year-old man was charged with wounding.
• July 6: A woman was shot at a property on Dawson Rd, Clover Park in South Auckland. Two young men, aged 17 and 20, were charged with wounding.
• May 25: Samiuela Anania Tupou was fatally shot at Seaside Park in the Auckland suburb of Ōtāhuhu.Two men charged with murdering the 21-year-old have pleaded not guilty.
• May 17: Joseph Siaosi was fatally shot by an occupant of a car as he walked away from a confrontation in South Auckland. The 23-year-old died on the front lawn of the family home in Piako St, Ōtara. Two people have been charged in connection with the death.
• April 26: Killer Beez gang president Josh Masters was shot at a Harley Davidson store in the East Auckland suburb of Mt Wellington. Masters was hospitalised in a critical condition. A 39-year-old man was charged with attempted murder.
• April 20: Father-of-five Siaosi Tulua, 39, was fatally shot at his home on Darnell Cres, in Clover Park. A 22-year-old has been charged with his murder.
• March 13: Arthur (Afa) Brown, 26, was fatally shot on Vine St in Māngere just before 1am. A 20-year-old male has pleaded not guilty to murder.