The Fukushima No. 1 nuclear plant crisis was caused by Tokyo Electric Power Co.'s lack of preparation for huge tsunami and exacerbated by conflicting levels of authority and downright "distrust and meddling" by high-ranking officials, an independent investigative panel reported Tuesday.

"There were cases of excessive meddling (by the government) toward people working at the site," and such actions did more harm than good, said Koichi Kitazawa, former chief of the Japan Science and Technology Agency.

The investigative group Kitazawa leads, the Rebuild Japan Initiative Foundation, interviewed more than 300 politicians, bureaucrats and workers involved in the Fukushima crisis for its report.