Chinese authorities have launched an investigation into the business activities of Ye Jianming, the head of CEFC, according to media reports. The company is a fast-moving conglomerate with interests in the oil industry and ambitions in overseas media.

Reports of the probe surfaced Thursday in Chinese financial investigative publication Caixin. The Reuters news agency, citing its own sources, later said Ye was being investigated for “economic crimes,” a catch-all description that usually points to a corruption inquiry.

CEFC was founded in 2002 as a small oil trader and has grown rapidly through acquisitions. With share listings on both the Shenzhen and Hong Kong stock exchanges, CEFC is currently contracted to pay $9 billion for a 14% stake in Russian energy giant Rosneft.

In late December, it was reported that CEFC had joined forces with Czech-Slovak finance group Penta Investments to make a $2 billion bid for Central European Media Enterprises (CME), a large media group operating across much of East Europe. It is unclear if the CME bid will proceed and what impact the investigation into Ye will have on the Rosneft deal, which is imminently due to be completed.

The investigation into Ye appears to be yet another example of central government authorities in China reining in the overseas activities of Chinese conglomerates. Some have been suspected of engaging in overseas acquisition sprees in order to shift their capital offshore; others are suspected of helping corrupt Chinese officials move illegal assets abroad by overpaying for foreign target companies.

Last week Chinese authorities took direct control of Anbang Insurance, a formerly free-wheeling conglomerate. Another big company, property and airlines group HNA, has been forced into a retreat that includes asset sales and job cuts. This week it was reported that HNA will eliminate 100,000 jobs, or a quarter of its workforce.

Other companies seem to be faring better after a series of setbacks, including Dalian Wanda, which still has strong core businesses in commercial property and movie theaters, and Fosun, which owns a majority stake in Jeff Robinov’s Studio 8 and a piece of Cirque du Soleil. Fosun recently saw the collapse of its bid for Italian lingerie firm La Perla. But this week Fosun announced the purchase of a Brazilian insurance company and French fashion house Lanvin.

CEFC Anhui shares in Shenzhen were down 10%, which would normally trigger the circuit breakers that halt trading for the day. But later Thursday they appeared to be down just 6% at RMB5.10 apiece. Shares in CEFC Hong Kong Financial Investment crashed by 24% to HK$0.60 in early afternoon trading.