Police have spoken with two people spotted moments before Christchurch's Port Hills fire was discovered, last Wednesday

Our newsroom's spoken with residents near Hoon Hay Valley Road, who claim to have seen two people around a walking track on the hill followed by smoke.

The residents took photos of the car the pair drove off in, and alerted police.

A police spokesperson says officers have spoken with the people, who are considered 'likely witnesses'.

Meanwhile, confirmation 337 people have provided photographs and video of the fire's earliest moments.

Firefighters remain at the scene of the 650-hectare blaze, for a seventh day.