The Japanese nuclear watchdog has officially raised the incident level of the recent leak of radioactive water from the wrecked Fukushima Dai-ichi nuclear from a level 1 to a level 3 on the international scale.
That puts the 300-ton leak at the level of a "serious incident".
The Nuclear Regulation Authority proposed the increase last week but confirmed it Wednesday after a meeting with the International Atomic Energy Agency.
The overall Fukushima nuclear crisis, which started after Japan was rocked by a devastating earthquake and tsunami in March 2011, has been rated at the maximum level of 7, on par with the 1986 Chernobyl disaster.
Regulatory officials put the Tokyo Electric Power Co. (TEPCO) in the hot seat by claiming they ignored their instructions for better patrolling procedures to reduce the risk of overlooking leaks.
More from GlobalPost: The Fukushima nuclear complex is still not under control
The day before, TEPCO acknowledged that highly radioactive water had been leaking out of the defunct plant for nearly six weeks before it was discovered on August 19.
The nuclear watchdog said that TEPCO lacked expertise to handle the fallout from the nuclear disaster.
"Their instructions, written or verbal, have never been observed," Toyoshi Fuketa, a regulatory commissioner, said at the agency's weekly meeting Wednesday.
TEPCO quickly constructed around 350 storage tanks to hold radioactive water after the original meltdown.
According to local media reports, the tanks were held together with bolts and resin and not sealed with welding.
The the tanks are still plagued by leaks more than two years after the initial disaster, raising concerns about contamination of the ocean.
TEPCO recently admitted that only two employees were assigned to check all 1,000 storage tanks at the plant.
The workers did not carry dosimeters and their inspection results were not adequately recorded, reports the Associated Press.
The company has pledged to increase its monitoring staff to 50 from eight.