The French military has confirmed it is continuing to monitor the stability of Moruroa atoll in French Polynesia, but says there is no current risk of collapse at the former nuclear testing site.
The atoll was used until 1996 for more than 130 underground blasts and remains a closely monitored military exclusion zone.
Rear Admiral Anne Cullere, joint armed forces commander in French Polynesia, has told , the French military has a responsibility to monitor the site.
"The risk for the moment is evaluated up to zero even though there is no 'nil' risk so we'll be keeping on this surveillance for years to come probably," she said.
The French High Commissioner Jean-Pierre Laflaquiere has dispelled concerns about a possible atoll collapse that could trigger a 20-metre high wave.
Commander Cullere agrees, saying their monitoring equipment would give them one to two weeks warning of any potential collapse.
"In the worst, the very worst scenario, there could be a wave out there of about 1-1.5 metres, which could mean that the coral reef out there in Tureia would be flooded," she said.
"So it means that people fishing on foot would have to be warned beforehand."
Commander Cullere says the coral appears to have been destabilised during the nuclear testing, but there are no signs of further degradation.
"There's no crack in the surface," she said.
"I have 30 military living all year around on Moruroa, they are based in the lagoon, they live there, do you think if there was any danger I would leave them there?"
Commander Cullere has confirmed platforms have been built to provide a safe haven for the military personnel should a coral cliff collapse trigger a huge wave.
She's denied rumours of new construction taking place on the atoll, saying the platforms were built more that 30 years ago, and no new works are being carried out.
"As we understand it there is absolutely no construction and no building ongoing on Moruroa and there's no undersea mining at all," she said.
The Association of Former Nuclear Site Workers who took part in French nuclear testing on Moruroa claims it has evidence that the French government is building a laboratory, linked to plans for undersea mining.
They've called for French Polynesia's Senator, Richard Tueiava, to visit the atoll to survey any works.
Commander Cullere says if Senator Tueiava wants to visit to see for himself what's going on, there is absolutely no reason to stop him.