Russian officials said at the time that all nuclear weapons aboard the Yekaterinburg nuclear submarine had been unloaded well before a fire engulfed the 167-meter (550 feet) vessel and there had been no risk of a radiation leak.

But the respected Vlast weekly magazine quoted several sources in the Russian Navy as saying that throughout the fire on December 29 the submarine was carrying 16 R-29 intercontinental ballistic missiles, each armed with four nuclear warheads.

"Russia, for a day, was on the brink of the biggest catastrophe since the time of Chernobyl," Vlast reported. The 1986 disaster in modern-day Ukraine is regarded as the world's worst nuclear accident.

Neither the Russian Defence Ministry nor the office of deputy prime minister Dmitry Rogozin, who has responsibility for military matters, would immediately comment on the report. A spokesman for the navy could not be contacted.