Japan’s government says it is a serious matter that beef contaminated with radioactive cesium has reached the domestic market.

But officials are also calling it an isolated incident, while vowing to increase inspections of food in wake of the country’s nuclear crisis.

Officials in Fukushima prefecture, where three reactors crippled by the March 11th earthquake and tsunami suffered meltdowns, are now acknowledging they are unable to totally prevent potentially contaminated food from reaching the marketplace.

That comes after confirmation by the central government that some beef from contaminated cattle in Fukushima has apparently been consumed.

Officials say inspections prevented some radioactive meat from reaching the market. But Noriyuki Shikata, a spokesman for the prime minister’s office, acknowledges that other contaminated cuts of beef slipped through.”The fact that these contaminated meats that exceeded our regulation limit was distributed to the market was very unfortunate,” said Shikata. “And from the government point of view we will be working on strengthening the monitoring in close collaboration with the municipalities and, of course, the government ministries in charge.”

A senior technical officer at the health ministry, Toshitaka Higashira, told reporters Wednesday the contaminated beef that was sold to shoppers and restaurants originated from six cattle on one farm in Fukushima prefecture.”The beef has been shipped to 11 prefectures throughout Japan and the total amount distributed on the market was 1,400 kilograms,” said Higashira.

The contaminated beef that was intercepted measured six times the allowable limit of radioactive cesium. Authorities say they presume the beef that was sold had the same radiation levels, which they say is not dangerous because only small portions would have been consumed.Officials blame a single rancher who ignored orders not to feed cattle rice straw which may have been exposed to radiation following explosions at the Fukushima-1 nuclear power plant in March.

The damaged reactors have yet to be brought to a cold shutdown state.  They continue to spew radiation into the atmosphere. Government officials say the levels detected continue to be relatively high to the northwest of the nuclear facility, but levels have remained steady since mid-April.

Since the natural disaster four months ago, which severely damaged the nuclear plant, a number of food products in northeastern Japan have been contaminated with levels exceeding legal limits. Beef is the newest item on the list which also includes milk, vegetables, fish and tea leaves.

At supermarkets here in Tokyo where items from the affected region are carried and certified safe to eat, they have been discounted but do not appear to be selling well.

By Yoree Koh

A prized Japanese watermelon fetched nearly $4,000 on Monday at an auction in Sapporo. Yes, $4,000.

But before you choke on your own slice of citrullus, that four-figure price tag is actually a steep fall from the fruit’s peak season several years ago, in what may be a sign that the country’s highly regarded luxury fruit market is the latest victim of tightening consumer purse strings.

The rare Densuke watermelon, a solidly black, smooth-as-a-bowling-ball gourd, sold on the first day of seasonal bidding for 300,000 yen, which translates into about $3,740, according to the Sapporo Central Wholesale Market. While the seeds aren’t gold, the fruit is lauded for its crispy texture and extra sweet juice. And grown exclusively in Hokkaido, there are only about 65 to 70 of the stripeless watermelons available each year.

The Isetan department store raised its paddle for the winning bid for the second consecutive year. The sweet watermelon is on display at its Shinjuku outlet in Tokyo until June 16. Business in business, though: An Isetan spokeswoman said the fruit will be sold whole for 315,000 yen.

While the final  Densuke auction block price ranks a couple thousand dollars above what most consumers would consider forking over for a variation of a summer fruit ubiquitous at neighborhood block party barbecues, it falls about as many short from the luxury fruit market’s heyday. The price of the Densuke watermelon – sold at wholesale markets in the country’s northernmost island of Hokkaido – has plunged about 200,000 yen since its peak at the Sapporo market in 2006 and 2007. The highest-ever paid price for the fruit was 650,000 yen, or about $8,100, at the Maruka Asahikawa Wholesale Market in 2007.

But still, even in a down year the Densuke watermelon is no steal for the ordinary consumer. And Japanese fruits in general are notoriously expensive compared to other countries. The fresh produce – crisp apples, fleshy peaches, juicy grapes– are treated with the utmost care, often scrubbed to a shine and perfectly nestled within white foam wrappers. A normal watermelon can cost about $30, and retailers can demand at least $10 for a pack of plump strawberries.

The Densuke isn’t the most prized of Japan’s watermelons. But even on that score, the going price for Sapporo market’s most expensive fruit, the Yubari melon, dropped by 500,000 yen this year to one million yen – or about $12,500 — on May 13. The sought-after Yubari is available at more affordable prices: a package of two-medium sized Yubari melons are currently being advertised as the perfect Father’s Day gift for 4,980 yen, for example.