Japan's prime minister at the time of the 2011 earthquake and tsunami has revealed that the country came within a paper-thin margin" of a nuclear disaster requiring the evacuation of 50 million people. In an interview with The Telegraph ... Naoto Kan described the panic and disarray at the highest levels of the Japanese government as it fought to control multiple meltdowns at the crippled Fukushima Daiichi nuclear power station. He said he considered evacuating the capital, Tokyo, along with all other areas within 160 miles of the plant, and declaring martial law. Mr Kan admitted he was frightened and said he got "no clear information" out of Tepco, the plant's operator. He was "very shocked" by the performance of Nobuaki Terasaka, his own government's key nuclear safety adviser. "We asked him - do you know anything about nuclear issues? And he said no, I majored in economics." Another member of Mr Kan's crisis working group, the then Tepco chairman, Tsunehisa Katsumata, was last week indicted on charges of criminal negligence for his role in the disaster. Mr Kan lost the prime ministership later in 2011. The former leader said that "a lot of the accident was caused before March 11" by the complacency and misjudgment of Tepco, a verdict echoed by the official inquiry, which dubbed the nuclear accident a "man-made disaster". The criminal investigation which led to last week's charges against Mr Katsumata and two other Tepco managers found that they had known since June 2009 that the plant was vulnerable.