He was last night in a critical condition at Auckland Hospital.
The Herald confirmed last night with various sources that the victim was Masters, the president of the Killer Beez gang who was released from prison in July.
There is thought to have been rising tensions between his and other gangs, a source said.
A 39-year-old man has been arrested and charged with attempted murder in relation to the shooting, Detective Inspector Tofilau Fa'a Va'aelua of Counties Manukau Police said this morning.
"The victim remains in a critical condition in hospital. Police are not seeking anyone else in relation to this incident."
Masters spent 10 years and five months in jail on drugs and money laundering charges.
One of the conditions of his release was that he was not allowed to associate with gang members, except for those approved by his probation officer, or enter gang-related premises.
Tributes for Masters have started appearing online. One person wished for his "speedy recovery King Killer".
Earlier yesterday, Detective Inspector Tofilau Faa Vaaelua said police were called to the Mt Wellington store at around 1.50pm following reports of a shooting.
The incident was captured on CCTV.
A worker at a cafe across the road said they could hear a woman screaming next to an ambulance outside on the road soon after the incident occurred.
A staff member who answered the phone at the motorcycle store said they could not comment and hung up.