Even Auckland Peace Action, a community peace campaign formed in opposition to war and war profiteering in Aotearoa NZ and the world, denounced the planned activities and urged the NZDF to halt them.
"We are disappointed, disturbed and disgusted that the Royal New Zealand Navy is practising killing protesters," the group claimed in a media release.
"We are concerned that if the NZ Royal Navy was to go ahead with simulating an attack on civilians exercising their human and democratic rights, then the Navy would be simulating and performing a crime against humanity.
"It is appalling and inappropriate. We have the right to protest and should not be subject to the threat of military violence."
However, a NZDF spokesperson told the Herald that people have misunderstood the intentions of the exercise.
"To suggest that the Royal New Zealand Navy is practising 'killing protesters', in the words of Auckland Peace Action, is both absurd and abhorrent.
"This exercise taking place in Kauri Pt is both routine and long-planned and entirely unconnected with protest events taking place around the world."
The NZDF spokesperson added that the exercise is part of routine HMNZS Otago preparation for operational activities and the scenario is set in a fictitious overseas location.
One aspect of the exercise involves Navy personnel playing the part of those with hostile intent towards the ship and crew, they explained.
"The ship's 'work up', as these exercises are called, is intended to allow the ship and her crew to maintain readiness for a number of situations that they may encounter, as is required by the Government.
"These range from person overboard and firefighting drills to how to deal with a drone incursion, and how to ensure the safety of the ship and crew in the face of attempts to board it.
"This particular exercise [involving simulated protesters] would prepare the ship and crew for docking in a country where unrest is occurring, and where the vessel may be evacuating civilians, refuelling and resupplying, or taking part in security operations."
The NZDF spokesperson said as practice, the Navy informed the public about the exercise in order to avoid alarming the community, who may hear loud noises.