UPDATE 1-Japan halts beef from Wisconsin Smithfield plant

(Adds JBS comment in paragraph 3, USDA comments in paragraphs 7-8)

TOKYO, Dec 11 (Reuters) - Japan has suspended imports from a former Smithfield Beef Group meatpacking plant in Wisconsin after it found meat that could not be verified as coming from cattle aged 20 months or less, the farm ministry said on Thursday.

The ministry said it had asked the United States to look into the matter, adding that imports from the Green Bay plant that shipped the cargo would be halted until it received a report on the issue.

Smithfield Foods Inc SFD.N sold its beef plants and cattle feeding operations to Brazilian beef company JBS SA JBSSS3.SA in October for $565 million.

JBS said it is investigating and is “working with both the U.S. and Japanese agencies to resolve the matter.”

Quarantine officials spotted a discrepancy in one package of a six-tonne cargo of frozen beef tongue from the U.S. plant that arrived in Japan on November 17, the ministry said in a statement.

The results of an inquiry by the importer, submitted to the ministry on Wednesday, showed it was not possible to trace the age of the cattle for a total of 25.6 kg of meat from the cargo.

Amanda Eamich, a spokeswoman for the U.S. Agriculture Department’s Food Safety and Inspection Service, said the department is looking into what happened but did not have a timetable on when the review would be completed.

“It was most likely a mistake but we are looking into it just to make sure, and the Japanese did ask us to look into it,” said Eamich, who noted the shipment was most likely mispacked.

Tokyo currently only allows imports of U.S. beef from cattle aged 20 months or less after it lifted a ban first imposed in December 2003, following a U.S. report of a case of mad cow disease.

Imports have resumed after checks were implemented and safety concerns were addressed. The United States was a top supplier of beef to Japan prior to the ban, but imports have been slow to return to pre-ban levels due to the age limit. (Additional reporting by Christopher Doering in Washington; Editing by Christian Wiessner) (Reporting by Miho Yoshikawa; Editing by Clarence Fernandez)