"Look at advanced Japan," he said. "People are housed in stadiums and are lying about on the floors of sports halls in unhygienic conditions."

Gen Antoshkin said he thought the Japanese were simply unable to cope on their own. "It is clear that they do not have enough strength or means. They need to ask the international community for help," he said. "I think the Japanese catastrophe is already more serious than Chernobyl. The main thing is that they do not allow it to become three, four or five times more serious."

Gen Antoshkin, 68, was in charge of Soviet pilots who flew over Chernobyl's stricken fourth reactor, dropping lead, sand and clay from the air to try to contain radiation. In the ten days after the accident on 26 April 1986, his pilots flew 4,000 such flights, exposing themselves to huge radiation doses.

Gen Antoshkin insisted that his men, many of whom later died from cancer, knew the risks they were taking. "Of course the pilots knew (they were getting high doses) and the consequences," he said. "But the pilots knew that the reactor needed to be covered as quickly as possible. You'd tell the pilot to leave but he'd come back."

Radiation levels were so high that they were off the scale, he added, and precautions were as basic as being told to change uniform and have a good wash.