What is this mystery plume of smoke in the sky?
The cloud, which was photographed by Alexia Russell of Newstalk ZB when it appeared yesterday evening over Hobsonville in Auckland, has sparked curiosity on social media.
In a post on Facebook, Ms Russell described the plume as a "strange light".
Others mused the trail could be a "Kim Jong Un missile test" or "aliens".
MetService meteorologist Derek Holland said the plume had most likely been caused by a plane.