It has been 50 years since the HMNZS Otago and HMNZS Canterbury sailed to the Mururoa atoll in French Polynesia to protest French nuclear testing in the Pacific.
Sailors on both vessels witnessed tests while they were there.
At the time, little was known about the impacts of radiation exposure but a University of Otago study conducted in 2020 found that navy veterans who were aboard the ships have higher rates of cancer than the general population.
Gavin Smith was on board the Canterbury as a lead engineering mechanic. He is now president of the Mururoa Nuclear Veterans Group and advocates for genetic testing for Mururoa veterans and their descendents.
Smith spoke to Kim Hill.