For the first time, the French government has been confronted with scientific evidence that its nuclear tests in the Pacific caused an increase in cancer on the nearest inhabited islands.
A survey by an official French medical research body has found a "small but clear" increase in thyroid cancer among people living within 1,000 miles of nuclear tests on French-owned Polynesian atolls between 1969 and 1996. The results, yet to be officially published, are likely to bring a flurry of compensation claims from civilians and former French military personnel who were involved in the tests.
They will also reopen the controversy in the Pacific - and in Australia and New Zealand - surrounding President Jacques Chirac's decision to resume the tests soon after he became president in 1995.
France has since abandoned all experimental nuclear explosions. Florent de Vathaire, an expert on cancer epidemics at the French medical research body Inserm, said: "We have established a link between the fall-out from French nuclear tests and an increased risk of cancer of the thyroid."
A study was made on 239 thyroid cancer cases in the region up to 1999, three years after the last French test. Only 10 cancer cases over 30 years can be attributed directly to the tests, M. de Vathaire said, but this was "significant" and enough to justify further research.
He called on the French defence ministry to finance more studies, including the examination of military personnel who worked on the nuclear programme in the Pacific.
The detailed results of M. de Vathaire's study will be published shortly in a scientific journal but the main findings have been released in advance to fulfil a promise that the people of the French-owned Polynesian islands would be the first to be informed.
Officially, France has never recognised that its Pacific nuclear tests could endanger the health of its own Polynesian citizens, and that of other populations. The brief resumption of nuclear tests at Mururoa atoll in 1996 was justified on the ground that there was no possible threat to human health.
A pressure group for military personnel involved in the tests said the team's findings should force a change in French official attitudes. The Association des Vétérans des Essais Nucléaires said: "France is one of the last countries in the world to admit that nuclear tests were dangerous to health. The United States has recognised by law since 1988 that 31 kinds of illness, including 25 kinds of cancer, can be provoked among people living within 700 kilometres (435 miles) of point zero (the explosion site)."
The ministry of defence in Paris refused to comment on the findings until they were officially published.
France conducted 210 nuclear tests between 13 February 1960 and 27 July 1996. The first 17 explosions, in the period up to 1966, were detonated in North Africa, four in the atmosphere and 13 underground.
Between 1966 and 1996, France conducted 193 tests at Mururoa and Fangataufa atolls in the Pacific (46 in the atmosphere and 147 underground). France has had to admit that some of these explosions caused dangerous levels of radiation in the nearest inhabited islands.
After two tests within 17 days in 1966, radiation at five times the permitted annual dose was measured on the Gambier islands. After three tests in 1974, radiation equivalent to the entire permitted annual dose was measured in Tahiti.