TOKYO (AP)--Japan has suspended imports of U.S. long-grain rice following a positive test for trace amounts of a genetically modified strain not approved for human consumption, a news report said Sunday.

Japan's Health Ministry imposed the suspension on Saturday after being informed by U.S. federal officials that trace amounts of the unapproved strain had been discovered in commercially available long-grain rice, the Asahi newspaper said.

The genetically engineered rice was detected by Bayer CropScience AG. The German company then notified U.S. officials. The strain is not approved for sale in the U.S., but two other strains of rice with the same genetically engineered protein are.

The ministry will instruct companies not to process or sell any U.S. long-grain rice they may already have imported, though it has so far not received any report this year that any company has imported or plans to import such rice, the Asahi said.

The ministry has requested the U.S. government to enact strict controls, the Asahi said, adding that the suspension does not affect short- and medium-grain rice imports.

The Health Ministry does not include any strain of rice on its list of genetically modified foods approved for sale in Japan.

Health Ministry officials were unavailable for comment Sunday.