Radiation in water of an underground tunnel outside a turbine building of Number 2 reactor at Japan's crippled nuclear complex was more than 10,000 times above normal levels in reactors, the plant operator was quoted by Kyodo news agency as saying today.
The operator also found radiation in groundwater near a turbine building of the Number 1 reactor of the Fukushima Daiichi plant, Kyodo added.
And an abnormal level of radioactive caesium has been found in beef from the area, it said.
Earlier French president Nicolas Sarkozy today proposed a meeting of G20 nuclear industry officials in May to start hammering out new global safety standards in the wake of the power plant disaster in Japan.
Japan's battle to avert a catastrophic meltdown of fuel rods at the earthquake-wrecked facility north of Tokyo has triggered alarm and safety reviews in nuclear-powered countries around the world.
Mr Sarkozy, the first foreign leader to visit Japan since the March 11th disaster, said the incident should not cast doubt on the wisdom of pursuing nuclear energy itself but on the lack of international norms for ensuring the industry remains safe.
"The problem is more about establishing safety norms than it is about the choice of nuclear energy, for this there is no alternative right now," he told a news conference with Japanese prime minister Naoto Kan in Tokyo.
"We must address this anomaly that there are no international safety norms for nuclear matters. We want international standards because the world is a village and what happens in Japan can have consequences elsewhere."
He said France would ask the nuclear safety authorities of the Group of 20 countries to meet in Paris in May to lay groundwork for a special meeting of International Atomic Energy Agency (IAEA) conference the following month.
"We need international safety standards before the end of the year," said Sarkozy, whose country heads the G20 and G8 for most of 2011.
The IAEA draws up nuclear safety standards and recommendations, but they are not legally binding. Nuclear safety is primarily the responsibility of member states.
There is, however, a Convention on Nuclear Safety drawn up after the accidents at Three Mile Island in the United States and Chernobyl in Ukraine which obliges its signatories, currently 72, to achieve and maintain a high level of safety, largely based on the IAEA principles.
Mr Kan backed the French proposal for a global nuclear review, saying it was Japan's "duty to accurately share with the world our experience".
Mr Sarkozy, who flew to Tokyo after addressing a G20 seminar in China on global monetary reform, told Japan it had the support of the whole world as it strives to contain its nuclear calamity and deal with the aftermath of the earthquake and tsunami that left some 28,000 people dead or missing.
A team of French nuclear experts, including the CEO of state-owned Areva flew to Tokyo earlier this week to help Tokyo Electric Power (Tepco) as it battles to bring its crippled Fukushima plant under control.
France is the world's most nuclear-dependent country, producing 75 per cent of its electricity from 58 reactors.
"Consider me your employee," Areva chief executive Anne Lauvergeon told Japanese officials.
At a meeting with French expatriates in Tokyo earlier, Mr Sarkozy acknowledged that when France became the first country to tell its nationals to leave the city because of the nuclear disaster it "met with some ridicule".
France has since changed its advice.
"All the experts agree that living in Tokyo now does not represent a health risk," Mr Sarkozy said.
Reuters