In light of Wednesday's news that Japan's nuclear watchdog recommended elevating the situation at the Fukushima nuclear campus to a level-three "serious threat," a new wave of criticism has poured in, with some experts suggesting the situation at the crippled nuclear reactor is much worst than Japan or the plant's operator, Tokyo Electric Power Co. (Tepco) is willing to admit.

Mycle Schneider, a nuclear expert who has advised the French and German governments on nuclear issues, told the BBC that water is likely leaking from all around the Fukushima Daiichi nuclear campus and that there is no accurate measurement for radiation levels.

It came to light this week that a hastily-put-together storage tank had leaked about 300 metric tons of highly contaminated water and much of it has seeped into the ground. That leak is separate from other leaks happening from within the drainage systems in place in the nuclear campus' three melted down reactors, which are being perpetually flooded with water to keep the reactor cores from overheating. About 400 tons of water is injected into the reactors each day, and just as much contaminated water has to be extracted daily and stored in tanks around the campus. Space is quickly running short. Much of water is seeping through cracks in the reactor buildings and in the drainage system, where experts believe it is mixing with groundwater and flowing into the Pacific Ocean.

"Once it gets into the ground water, like a river flowing to the sea, you can't really stop a ground water flow. You can pump out water, but how many tanks can you keep putting on site?" asked Ken Buesseler, a senior scientist at Woods Hole Oceanographic Institution who has examined the waters around Fukushima. "There's no way to really contain all of this radioactive water on site," he told the BBC.

Nuclear expert Schneider said "the quantities of water they are dealing with are absolutely gigantic."

"What is the worse is the water leakage everywhere else -- not just from the tanks. It is leaking out from the basements, it is leaking out from the cracks all over the place. Nobody can measure that."

Schneider also suggests that the nature of the storage tanks, many of which are quickly assembled in order to deal with the huge quantities of contaminated water needing to be stored, could place the situation further in jeopardy.

"It is much worse than we have been led to believe, much worse," Schneider said.

Shunichi Tanaka, head of Japan's nuclear regulation authority, said he feared further leaks.

"We should assume that what has happened once could happen again, and prepare for more. We are in a situation where there is no time to waste," he told reporters at a news conference this week. "This is what we have been fearing. We cannot waste even a minute."