The Navy is investigating four staff accused of using illegal substances while deployed overseas on the frigate HMNZS Te Kaha.
Three crew members have been removed from their duties and sent back to New Zealand after Australian police were reportedly called in while the ship was docked at Cairns.
Te Kaha was searched and was found to be clear of banned substances.
Arrangements are being made to send home the fourth person.
The HMNZS Te Kaha is travelling to the world's largest international maritime exercise in Hawaii.
Newshub.
