The Department of Conservation (DOC) is investigating reports that Moko the dolphin was injured when he was hit with an oar by an irate woman in a waka in the Bay of Plenty.

The incident apparently happened on Wednesday in Omaio Bay, 56km northeast of Opotiki.

Moko, who has made the East Coast home since 2007, last week followed a fishing boat out of Gisborne headed for the Bay of Plenty.

It was understood Moko was being boisterous with waka ama boats in the bay, preventing them from returning to shore by pushing and bumping into their hulls.

It was believed a paddler training in the bay lost patience with Moko and hit him with an oar, possibly breaking it and cutting him.

DOC Gisborne/Whakatane area manager Andy Bassett said his staff had heard hearsay reports of Moko being injured, but had not been able to confirm them.

"We are keen for anyone who can substantiate the allegations of Moko being mistreated to contact DOC."

The dolphin was seen playing with swimmers after the alleged incident, however, though a witness said he was skittish and reluctant to approach people for a while.

Other paddlers reported being blocked from coming to shore by Moko on Wednesday, but at least one said she was not too bothered by the dolphin's antics.

Ruihi Walker, 17, said she and a friend took a waka ama boat out to see Moko in Omaio Bay.

"We thought he would be okay, and we had fun for a while playing with him and stuff, but when we went to go back in he wouldn't let us -- he wanted to keep playing.

"He kept bumping our boat, and we were only in a little two-man so he could push it quite easily.

"It was a bit scary at first. We thought we wouldn't be able to get back into shore, but then it was fun. We knew he was just playing.

"Luckily there was a bigger boat not far from us so we called that over and left it with Moko while we paddled to shore. That boat was too big for him to push, so they were all right."