The statement said the harbourmaster expected to be in a position to remove the zone early this week.
Bay of Plenty Harbourmaster Jon Jon Peters said the incident was under investigation by Maritime New Zealand.
He confirmed the ship had been anchored since late Monday last week, and the vessel was anchored 6.5km from the shore.
He said there were no safety concerns regarding the situation, and there was no impact on shipping traffic or marine life.
“With regards to the initial response and details around what happened, this matter is under investigation by Maritime New Zealand.”
Peters said a “number of parties” including Maritime New Zealand, the owner of the vessel and the Port of Tauranga were meeting today for an update from the owner of the vessel, including expected timeframes and the best way forward.