Japan has halted beef imports from a US packing plant after finding meat that could not be confirmed to comply with its restrictions, according to Japanese Government officials.

While the violation has been reported as the 15th by US beef supplies in four years, it is only the second for almost two years.

In reporting the halt, Reuters News Agency said the number of cases of violations has declined compared with that in the first few years after July 2006, when Japan resumed US imports after a temporary halt due to concerns over the risk of mad cow disease.

The latest issue relates to the inclusion of beef without proper documents in a cargo checked on October 17. The beef was exported by Tyson Fresh Meats in Hillsdale, Illinois.

Reuters reported that Japanese offiicials are waiting on detail reports on investigations into the incident by US authorities.

Japanese officials told the news agency that US authorities had reported they could not confirm the beef in the shipment was from cattle aged 20 months or less. Japan is said to be considering relaxing restrictions to allow beef from US cattle that were 30 months or younger, but currently restricts US imports to beef from cattle aged 20 months or less.

Tyson Foods Inc Manager Public Relations Worth Sparkman told Reuters: "One of our beef processing plants has been suspended from exporting to Japan pending a review of an order discrepancy. We are working with the Japanese government to review the facts and it is our hope the matter will be resolved quickly."

An official from Japan's health ministry said: "It is regrettable to make this announcement." It is the first violation case this fiscal year which started in April 2011, and there was only one case in 2010/11, the official said.

"We're scheduled to ask the views of our panel of experts about the risk of BSE at home and abroad on October 31, with the latest facts and findings provided," he added.

Reuters said the October 31 meeting is expected to pave the way for the country's independent Food Safety Commission to make the first assessment in five years on the risks from the disease, a necessary step for the Japanese government to decide whether to relax the rules on imports of US beef.

U.S-Japan bilateral talks on deregulating the restrictions had been deadlocked since mid-2007, when the last face-to-face negotiations were held, but resumed in September last year when a working-level meeting was held in San Francisco