A small amount of new oil washed up on Himatangi Beach on the Manawatu coast overnight.
Blobs of oil were first spotted on Waitarere, Foxton, Himatangi and Tangimoana beaches on Monday, and 90 people have been continuing the cleanup effort this morning.
Horizons Regional Council on-scene commander Ian Lowe said it hoped to clear all the larger patches of oil today before combing the beach again.
Himatangi and Foxton beaches remain closed to vehicle access during the cleanup.
Samples of the oil have been sent away for testing to try to determine the source of the spill.