A panel has upheld a decision by prosecutors not to indict three former senior officials of the Nuclear and Industrial Safety Agency over the Fukushima crisis. The agency was responsible for nuclear safety at the time of the accident and has since been dissolved.

The decision by the Tokyo No. 1 Committee for the Inquest of Prosecution, dated April 14, means that the agency is effectively absolved of criminal responsibility for one of the world's worst nuclear disasters.

The three were accused of professional negligence resulting in death and injury. They include Yoshinori Moriyama, NISA's former deputy director general for nuclear accident measures.

Tsunami waves flooded the plant on March 11, 2011, knocking out power supplies and causing three reactors to melt down.

The 11-member panel concluded that it was impossible for Moriyama and the two others to foresee that 10-meter-high waves would strike.

Three former Tepco executives, including then Chairman Tsunehisa Katsumata, 76, were indicted in February based on a decision by another committee that examined a prior decision by prosecutors not to lay charges.

Under the revised inquest of prosecution law, which took effect in May 2009, criminal charges are filed if a minimum of eight members of the judicial panel vote in favor of indictment in two consecutive rulings.

NISA was scrapped in September 2012 as the nation revamped its nuclear regulatory setup following the Fukushima crisis. Critics accused the agency of lacking teeth because it was under the umbrella of the pro-nuclear Economy, Trade and Industry Ministry and therefore was seen as hand in glove with the nuclear industry.