BEIJING — News reports say a Chinese oil tycoon whose company is buying a stake in Russia’s Rosneft has been detained by Chinese authorities for questioning in the midst of a sprawling anti-corruption crackdown.

The business news magazine Caixin, citing unidentified sources, reported Thursday that Ye Jianming of CEFC China Energy was under investigation but gave no details. The Hong Kong newspaper South China Morning Post said he was detained Feb. 16 on the orders of Chinese President Xi Jinping.

Ye’s company agreed last year to pay $9 billion for 14 percent of Rosneft, Russia’s biggest oil producer.

A former Hong Kong official who headed a think tank supported by Ye’s company was arrested in November in New York City on charges of moving bribes for African officials through U.S. financial institutions.