A welding contractor has been killed in a "huge" explosion at a factory in Wiri, in South Auckland.
At 1.36pm emergency services began receiving multiple reports of a large explosion at what is understood to be oil recycling plant Salter's Cartage in Bolderwood Place.
Cordons which were in place during the incident have since been removed, and roads in the area reopened.
A fire communications spokesperson earlier said firefighters described a "huge" explosion.
Counties Manukau Police spokeswoman Shelley Nahr told ONE News a person had died from the explosion.
Police later added that the man who died was a contractor, and the death will be investigated by police and WorkSafe New Zealand.
Witness Jason Farquhar said he saw the man standing on the roof of a petrol container (which he described as like a silo), and he appeared to be welding.
He said he heard "a pretty big bang … like a sonic boom," and saw a "shock wave" when the explosion occurred.
He said the person was thrown in the air far away from the container.
Witness Vineet Thakur said he saw a "big explosion and we saw some things going up in the sky".
An attendant at the Z petrol station on Roscommon Rd told ONE News he felt the explosion "on the roof and in the glass".
"It was a loud noise - like a thunderstorm," he said.
He said witnesses had come into the station and told him a person had been blown into the air by the explosion and killed.
A ONE News reporter at the scene said the air smelt heavily of gas.
A 111 caller from a block away from the explosion reported that pictures had been blow off their wall.
Salter's was founded in 1980 and established itself as the industry leader in hazardous recycling disposal in New Zealand, the company's website states.