Japan confirmed the presence of radioactive iodine contamination in food products from near the crippled Fukushima nuclear power station and ordered a halt to the sale of such products from the area.

The government said they had found higher than normal levels of radioactive materials in spinach and milk at farms near the ravaged plants, reports The New York Times.

Traces of radioactive iodine were also detected in tap water in Tokyo and several prefectures near the atomic power complex, a science ministry official said, but the levels were well “below the legal limit”.

In what it called another "critical" measure to counter the contamination of food products, the International Atomic Energy Agency (IAEA) said Japanese authorities on March 16 recommended that people leaving the area should ingest stable iodine.

Taken as pills or syrup, stable iodine can be used to help protect against thyroid cancer in the case of radioactive exposure in a nuclear accident, Reuters reports.

"Though radioactive iodine has a short half-life of about 8 days and decays naturally within a matter of weeks, there is a short-term risk to human health if radioactive iodine in food is absorbed into the human body," the IAEA said in a statement.

The findings are nevertheless likely to fuel consumer fears in the wake of last week's quake and tsunami, which critically damaged the Fukushima No 1 plant northeast of Tokyo, sending radioactive substances leaking into the air.

"Radiation exceeding the limit under Japanese law was detected," government spokesman Yukio Edano told reporters.

The contaminated milk was found in Fukushima prefecture, where the quake-damaged atomic power station is located, while the tainted spinach was discovered in neighbouring Ibaraki prefecture, Edano told reporters.

The milk was found more than 30 kilometres from the Fukushima No 1 nuclear power plant -- outside the government's exclusion zone.

The spokesman said the health ministry had ordered authorities in both prefectures to check where the products came from, how they were distributed and -- depending on their findings -- suspend sales.

"The government will do its utmost... to avoid health hazards and to resolve this problem," Edano said.

"The number does not present an immediate health threat. I would like to ask you to act calmly."

He noted that even if a consumer were to drink the contaminated milk for a year, the radiation level would be the equivalent of one hospital CT scan.

Hideki Mukaitsubo, president of Fukushima Prefecture Minami Dairy located in Izumizaki village, 60 kilometres from the nuclear plant, said he was concerned about the long-term prospects for the industry.

"We've halted shipping completely. I really don't know what to do from tomorrow," Mukaitsubo told AFP by telephone, criticising the government's "unclear" sampling methods.

"I don't know any more about my future," said Mukaitsubo, who takes milk from several local producers.

Yukihiro Ebisawa, an official at Japan Agricultural Cooperatives in Ibaraki prefecture, said they had received an order to tell spinach producers not to harvest or ship any more produce.

"We are worried... I hope the situation will calm down as soon as possible," Ebisawa told AFP.

'SOME STABILIZATION'

One of six crippled reactors appeared to stabilize yesterday as Japan raced to restore power to the stricken power plant to cool it and prevent a catastrophic release of radiation.

Engineers reported some rare success after fire trucks sprayed water for several hours on reactor No 3, widely considered the most dangerous at the ravaged Fukushima Daiichi nuclear complex because of its use of highly toxic plutonium.

"The situation there is stabilizing somewhat," Chief Cabinet Secretary Yukio Edano told a news conference.

Japan also reported its first contamination of food since the powerful March 11 earthquake and tsunami that has left nearly 18,000 people dead or missing, turned entire towns into debris-strewn wastelands and triggered a nuclear emergency.

A 1.5 km power cable was connected to the outside of the mangled plant in a desperate attempt to re-start water pumps that would cool overheating nuclear fuel rods and prevent a deadly radiation leak.

Four of the worst-hit reactors in the complex should have electricity by Sunday, Japan's nuclear safety agency said, a potentially crucial milestone in the world's worst nuclear accident in 25 years.

Restoring the plant's cooling system might help to allay anxiety in Tokyo, about 240 km (150 miles) to south where tens of thousands of tourists, expatriates and residents have either left or stayed indoors, despite radiation readings well within the average and winds blowing from the plant off to sea.

Engineers fixed the power cable to the No. 2 reactor but have yet to turn on its coolers, and they plan to test power in reactors No 1, 2, 3 and 4 today, Hidehiko Nishiyama, deputy director general at the Japan Nuclear and Industrial Safety Agency, told a news conference.

PUBLIC APOLOGY

Thousands living outside that danger zone but within a 30 km radius face dwindling supplies of heating fuel, food and water, heeding a government request to stay indoors and close all windows, doors and vents.

The operator of the 40-year-old plant, Tokyo Electric Power Co (Tepco), is facing mounting criticism in Japan, including questions over whether it hesitated too long before dousing the reactors with seawater, which permanently damages them.

Yesterday, its president issued a public apology for "causing such great concern and nuisance."

Tepco also apologised for the contamination of foodstuffs and said it would look into compensating the farmers affected, Jiji Press reported.