Firefighters contain blaze at Whittaker's Porirua chocolate factory

Firefighters have worked to contain a blaze that broke out at the Whittaker's chocolate factory in Porirua overnight.

A Fire and Emergency (FENZ) spokesperson told 1News it was alerted to the fire inside the factory in a chocolate hopper at the rear of the building shortly before 11pm.

A chocolate hopper is a manufacturing vessel that holds chocolate in liquid form.

Five fire trucks and an aerial fire truck were sent to the factory and had the fire contained by 11.20pm.

Wellington Free Ambulance said one patient was taken to Wellington Hospital in mild condition.

FENZ remained at the scene until 1am.

An investigator would return to the scene today to look for the cause.

In a statement to 1News, a Whittaker's spokesperson confirmed "all staff are safe" following yesterday's fire.

"It was confined to one piece of equipment and was very rapidly contained, but we are still assessing the damage," they said.

"We immediately activated our Emergency Response Plan and, as part of this, will be working to minimise any potential disruption to our business, which we think is minimal at this stage based on our preliminary assessment."