Police recently investigated a farmer in western Japan for selling wagyu beef cattle's sperm and fertilized eggs to a Japanese man who attempted to smuggle them to China, investigative sources said Sunday.

The livestock farmer in Tokushima Prefecture told the police in February he sold the sperm and the eggs for several million yen to a man he had never met before, the sources said.

The investigation came after Chinese authorities found the Japanese man carrying the sperm and eggs, stashed in straw-like containers, in July last year and did not allow him to enter the country.

The man, who did not go through the required procedure for exporting livestock and the like, told the police he was just asked by an acquaintance to carry the sperm and eggs to China. The police believe the man is different from the person who bought them from the Tokushima farmer.

The farmer did not follow necessary procedures to sell cattle sperm and eggs either, telling the police he was asked to sell them over the phone and did not know they would be taken out of the country, the sources said.

Japan has already seen other genetic resources smuggled to other countries. The agricultural ministry has said some plant varieties newly developed by Japanese farmers have been illegally taken out of the country, including certain strawberries and muscat grapes.