Police in Osaka, western Japan, have arrested two people on suspicion of illegally taking fertilized eggs of premium wagyu beef cattle to China.
Police say last July, Toshiki Ogura attempted to take hundreds of straw-like containers of frozen eggs and sperm to Shanghai by ferry. He was unable to get through customs there. Officials confiscated the items on his return to Japan.
A police investigation later found that Yusuke Maeda, a restaurant owner, asked Ogura to take the eggs out of the country.
Police arrested the men on Saturday under the domestic animal infectious diseases control act, which bans the export of cattle without quarantine.
Maeda told NHK that a Chinese acquaintance asked him to export the eggs, and that he didn't know they were from wagyu.
Police suspect the eggs and sperm came from a cattle farmer in Tokushima Prefecture, western Japan.
The farmer told NHK that he received a phone call in February last year asking for fertilized eggs. He said a stranger later came to pay for them.
Police are still trying to identify the intended recipients in China.
Wagyu refers to four Japanese breeds of beef cattle and their hybrids. The beef, which is soft and densely marbled with fat, is becoming popular overseas. Regional labels include Kobe beef and Matsusaka beef.