Less than 50 birds remain in the care of the Wildlife Response Centre after 23 little blue penguins were released by boat from the western side of Motiti Island on Sunday.

The penguins, originally from Sandy Bay, north of Panaturi Point, were released from the Coastguard's TECT Rescue vessel.

Penguins dive out of captivity from the Coastguard vessel and into their freedom near Motiti Island.

The release leaves 43 little blue penguins and one dotterel remaining in care at the Te Maunga oiled wildlife facility.

Works are underway to dismantle the majority of the facility although a few structures will be left standing until the last of the Rena is removed from the reef.

This enables a speedy response to rebuild the operation should the containers ship wrecked on the Astrolabe Reef cause a further environmental danger to wildlife.

Maritime New Zealand night operations to check on released birds are continuing and its staff are reporting few oiled birds are being found.

However, four oiled penguins were picked up over the weekend, two from Motiti Island and two from Mount Maunganui.

Motiti Island remains a priority work area with three teams looking for oiled wildlife at the southern end of it.

Coastguard volunteers were among those to release the penguins.

Some penguins preferred the vessel's port side from which to dive into the water from.

Carlijn Bouwman points a penguin in the right direction while another stands watch.