The first group of penguins affected by an oil spill off the coast of New Zealand have been released back into the wild.

The Rena ran aground off the Astrolabe reef on 5 October and more than 350 tonnes of oil have spilled from the ship into the ocean.

The 49 penguins are the first of 350 to be given a clean bill of health after being rescued and cleaned, and they have been microchipped so their progress over the next year can be monitored.

Wildlife response manager Kerri Morgan said it was "really nice to see that, for these birds, they are back where they belong".