Police in Nelson want to talk to a second person in connection with a suspicious fire that diverted some crews fighting the huge Pigeon Valley blaze.
The fire at Walter's Bluff broke out on 8 February, on a hillside above the city, and firefighters were able to get it under control.
Police have been looking to talk to a man seen eating while sitting on a bicycle on Iwa Road that day, and are now looking for a woman who was in the area.
They said she was driving a blue hatchback car near the Nelson School of Music on the corner of Collingwood Street, shortly before 4.30pm that afternoon.
She was also seen stopping and picking up and item on the road directly adjacent to the roundabout.