On Monday, Japan's national broadcaster, NHK, reported that a group of court-appointed lawyers had indicted Tsunehisa Katsumata, who was chairman of Tokyo Electric Power Co. (TEPCO) when the meltdown occurred, along with two other TEPCO executives.

The three men have been officially charged with negligence but were not detained by police.

Three reactors underwent meltdowns after an earthquake and tsunami hit the Fukushima Dai-ichi plant on Japan's eastern coast in March 2011, immensely damaging the facility. The meltdowns caused massive radiation leaks and tens of thousands of workers and nearby residents were forced to flee.

Investigative reports by the government and parliament said TEPCO's lax approach to safety and poor consideration of tsunami threats were directly linked to the catastrophe.

The indictment comes after a judicial committee ruled in July that the three suspects should face trial in criminal court after prosecutors had dropped the case.

However, experts say it may be difficult to prove criminal responsibility for failing to prevent the Fukushima meltdowns, but many, including the residents affected by the disaster, have said they hope that any trial would reveal more facts about the incident, including what TEPCO has not made public about the part it played.

The Fukushima disaster resulted in Japan taking all of its nuclear power reactors offline temporarily while safety checks were performed. Of the 43 functioning reactors in the country, only four have been put back in service.

av,es/kms (AFP, AP)