The septuagenarian, who was detained in the southern metropolis of Guangzhou, had three kilos of what are suspected to be illegal stimulants, Japanese officials said, citing Chinese authorities.
Chinese foreign ministry spokesman Hong Lei today confirmed that Takuma Sakuragi was detained on October 31 at Baiyun airport "for carrying drugs with him".
"He is now being detained in the detention centre of Guangdong province," Hong added.
Officials in the central Japanese city of Inazawa said Sakuragi is city councillor who was in China for his private trading business.
Also Read
The case comes after four Japanese nationals were executed in China in 2010 for carrying illegal drugs.
Possession of 50 or more grammes of so-called stimulant drugs such as methamphetamine can draw the death penalty in China, which is known for its harsh drug laws.
Japanese media quoted a longtime associate of Sakuragi as saying the five-term city politician may have been framed due to his hardline stance on diplomacy with neighbours China and South Korea.
Tokyo is embroiled in separate territorial rows with Beijing and Seoul which routinely accuse Japan of failing to atone for its military aggression during the first half of the 20th Century.
"There might be some political angle to this case.