MITO, Ibaraki Pref. -- Police on April 23 carried out a raid the head offices of the Power Reactor and Nuclear Fuel Development Corp. (PNC) in Tokyo and of its nuclear fuel reprocessing plant situated in Tokai, Ibaraki Prefecture, over a falsified report on the fire and explosion during Japan's worst nuclear accident last month.

Police conducted the raid on suspicions that a law controlling nuclear reactors was violated by the state-run firm. The law makes falsifying reports on accidents at such facilities a criminal offense.

The Ibaraki Prefectural Police raid followed the filing of a complaint by the Science and Technology Agency, the supervisor of PNC, on April 16 in which the firm and three of its officials were named. The complaint urged police to investigate a false report on the fire and explosion at the Tokai plant's bituminization facility March 11 which exposed 37 workers to radiation.

The PNC officials could be fined up to 200,000 yen, if convicted, and it marked the first time police have raided nuclear facilities in connection with an atomic plant accident.

On March 21, PNC submitted a falsified report to the agency saying that the fire at the bituminization facility was visually confirmed as having been extinguished at 10:22 a.m., 16 minutes after it started. But workers did not actually confirm the fire had been completely extinguished, and about 10 hours later an explosion occurred at a facility where low-level nuclear waste is solidified through a mixing process with asphalt for long-term storage.