A U.S. meat-processing plant that recently shipped beef containing banned cattle parts to Hong Kong passed a Japanese government inspection late last year, a high-ranking Japanese farm ministry official said Monday.

The inspection concluded that the Colorado plant, owned by Swift Beef Co., had "no problem," Vice Agriculture, Forestry and Fisheries Minister Mamoru Ishihara said at a press conference.

The plant was one of 11 United States plants inspected in December by officials from the farm ministry and the Health, Labor and Welfare Ministry to certify beef shipments to Japan.

Hong Kong suspended beef imports from the U.S. plant after it discovered banned bones in a shipment from the Swift plant during an inspection at Hong Kong airport Friday.

Japan reinstated its import ban on U.S. beef Jan. 20 after a spinal column, prohibited under a bilateral accord as a mad cow disease risk, was found in a veal shipment at Narita airport.

The incident happened only a month after Japan decided to partially lift a two-year-old ban on North American beef on condition imports were limited to meat from cattle aged up to 20 months old, and that the brains, spinal cords and other risk materials were removed before shipping. Hong Kong lifted its ban on American beef in December under similar conditions, including an age limit of 30 months.

"It was regrettable," Ishihara said, adding that Japan is looking into the incident.

The U.S. has been persistently urging Japan to resume American beef imports, describing the spinal cord incident as a fluke.

In a report sent to Japan last month, the U.S. Department of Agriculture said the shipment found at Narita was a "unique" case in which the exporters and inspectors were not adequately familiar with the export requirements.