The Raroa floating production storage and offloading vessel, owned by OMV New Zealand, is the source of two recent oil leaks.
Oil leaked from the vessel, which is permanently moored at Maari, on 20 November and 18 October.
OMV mobilised a helicopter to fly over the area with a trained observer. No oil was visible on the water. It is believed that the amount of oil leaked was very small, but work is still being done to confirm the actual volume, OMV New Zealand MD Wayne Kirk comments.
The company expects the oil will continue to break down naturally and will continue to monitor the situation carefully.
Production on the Raroa had been reduced while the source of leak was found.
OMV New Zealand is part of the global OMV Group, based in Austria, and operates the Maari oil field 80km off the Taranaki Coast.