The building on fire belonged to Freight Haulage, he said.
The company describes itself as the largest transporter of containerised goods in Southland, with over 40 years experience in freight handling.
Police had closed off Lake St, and fire crews were working from inside the cordon.
Staff from the building on fire had been evacuated but remained on the scene.
A neighbour said she had been about 100m from the warehouse when the fire started.
The smoke smelled like nothing she had encountered before and was similar to sulphur, she said.
Fire and Emergency Incident Controller Julian Tohiariki said crews will remain on the scene throughout the night to ensure the fire remains contained before efforts to remove any remaining fire fuels inside the building are made in the morning.
“People may still see smoke coming from the area, and we want to let people in the path of the smoke plume know that it is not toxic - it is similar to the smoke from a vegetation fire,” Tohiariki says.
“However, inhaling any smoke is hazardous to your health, so we encourage anyone encountering the smoke to stay indoors with their windows and doors closed.”
A Fire and Emergency New Zealand spokeswoman said crews from Invercargill and Kingswell stations were called to an alarm activation about 4.25pm.
As they responded, 111 calls were received indicating the building was on fire and the smoke was visible to crews.
Further appliances were called, and upon arrival the fire was discovered to be a building 50m by 30m which was well alight.
Six fire engines were now in attendance, as of 5pm, along with a command unit from Invercargill.
Drivers were being asked to avoid SH1 in the vicinity of the blaze.
