Four groups of independent experts will conduct another probe into the nuclear disaster at the Fukushima Daiichi nuclear power plant, the NHK TV channel said.
Four commissions, fully independent from the government, will begin their investigation in January.
Along with questioning eyewitnesses and employees if the disaster-stricken plant and its operator TEPCO, the experts will also study the previous government's response to the tragedy. Actions by then prime minister Naoto Kan and other supreme officials will come under scrutiny.
A powerful earthquake and tsunami wrecked the Fukushima Nuclear Power Plant's cooling systems on March 11, causing meltdown at three of its reactors. Radiation leaked into the atmosphere, soil and seawater, causing the world's worst nuclear disaster since Chernobyl.
The first report, released on Tuesday, criticized people who have been involved in nuclear disaster response and those in charge of managing and operating the nuclear power plant for "lacking the whole-picture viewpoint in nuclear disaster preparedness."
The Japanese premier announced on December 16 that cold shutdown of reactors One, Two and Three of the troubled nuclear power plant has been successfully performed.
Japan's long-term goal is to dismantle the reactors and extract nuclear fuel in the coming 30 or 40 years.