The Japanese authorities are battling to try to minimise the release of radiation from the Fukushima nuclear plant.
Highly radioactive water has been found outside one of the reactor buildings for the first time, officials say.
Earlier, the government strongly criticised the plant's operator, Tepco, over mistaken radiation readings.
Tepco announced that a highly radioactive pool of water was 100 times more radioactive than it actually was.
Nik Gowing speaks to Yukiya Amano, Director General of the International Atomic Energy Agency about the credibility of information from Tepco and the Japanese government.