Radioactive cesium exceeding the safety limit of 100 becquerels/kg was detected from one of 6 pigs shipped from a pig farm in Koriyama City, Fukushima Prefecture. The other 5 were also found with radioactive cesium, ranging from 11 Bq/kg to 78 Bq/kg.
First, from Yomiuri Shinbun (5/22/2012):
Radioactive cesium from pork produced in Koriyama City, Fukushima, voluntary shipment halt
Koriyama City in Fukushima Prefecture announced on May 22 that the meat from one of the pigs shipped by a pig farmer in the city was found with 107.2 Bq/kg of radioactive cesium, exceeding the national safety limit (100 Bq/kg).
According to the Ministry of Agriculture, Forestry and Fisheries, it is the first case of cesium detection from pork that exceeded the new safety limit introduced in April.
According to the city, the meat from 6 pigs that was shipped on May 21 was tested using the simplified method [NaI scintillation, most likely]. From the meat from one of the pigs, more than 50 Bq/kg of cesium was detected. After more detailed inspection [likely using germanium semiconductor detector], radioactive cesium exceeding the new safety limit was detected. The city has requested the voluntary halt of shipment of the meat from 5 pigs that passed the simplified test, so none of the meat is being sold in the market.
The city send an official to the pig farm on May 22 and interviewed, but the cause [for radioactive cesium in the meat] is not known yet. The city will test the formula feed and other feed for the pigs to try to identify the cause.
Koriyama City's press release on May 22, 2012 says the pork that was found with 107.2 Bq/kg of cesium will be destroyed, but the rest of the pork that tested lower than the safety limit (100 Bq/kg) is "supposed to be destroyed by the producer". That doesn't engender much confidence these days.