The Fire Service was called to Rocket Lab's Auckland warehouse last night where its understood smoke was coming out of batteries inside the warehouse.
Firefighters were called about 7pm to the scene on Airpark Drive, Mangere, close to Auckland Airport.
Five fire trucks and two ambulances attended the scene, including the command unit and hazardous materials unit.
Rocket Lab issued a statement confirmed the callout and said there was no fire - just smoke.
"No one was injured in the incident," the statement read.
"The Fire service is remaining on site as a precaution while the batteries return to a normal temperature."
St John checked over half a dozen workers who were in the warehouse.
Rocket Lab is behind the recent launch of 'Still Testing' the Electron rocket.