The Department of Conservation is investigating reports that Moko the dolphin was hit and harmed by a waka paddler.
It can't confirm yet whether Moko was hurt. However, there are some marks on the creature, who first attracted notice by playing with people in the water off Gisborne.
DoC says investigators have been interviewing people since the incident, which is believed to have occurred near Opotiki on Wednesday.
Area manager Andy Bassett says the report is being treated very seriously. He says DoC has been told a waka paddler hit the dolphin when it tried to stop the waka from going back to shore at Omaio, north-east of Opotiki.
Mr Bassett says it sounds like typical behaviour from Moko, who is known for being confrontational with people.
Moko is now based in the Whakatane area and has been seen playing with people near Whale Island.