A CEFC logo is seen at CEFC China Energy's Shanghai headquarter in Shanghai, China September 12, 2016. Picture taken September 12, 2016. REUTERS/ Aizhu Chen

SINGAPORE (Reuters Breakingviews) - Beijing’s grip is tightening. Authorities are now investigating the boss of fast-growing oil trader CEFC China Energy, the influential magazine Caixin reported on Thursday. This comes days after regulators took control of Anbang, a recklessly ambitious insurer. For foreign counterparties, it is ever harder to divine which private-sector leaders are vulnerable to, or shielded from, Beijing’s wrath.

Ye Jianming, CEFC’s youthful boss, had looked well-connected and untouchable. Even after Beijing ordered banks to review their lending to acquisitive conglomerates, banned some kinds of foreign deals, and whisked away Anbang boss Wu Xiaohui, he was striking bold deals.

In September, he agreed to buy a $9 billion stake in Russian oil giant Rosneft - the sort of high-profile, strategic deal that would usually be reserved for a national champion. CEFC had a contract to store part of China’s strategic oil reserve; enjoyed support from policy banks; and mused about CEFC rivalling Sinopec, the state-owned energy giant. He even bid for a stake in a central European media group – the kind of mission creep Beijing usually frowns upon. Now, a source with knowledge of the situation told Reuters Ye is suspected of committing “economic crimes”.

The rise and abrupt fall has, of course, become a repeated narrative in China. And not all tycoons have suffered the same fate: while the leaders of Anbang and Tomorrow Holdings are in deep trouble, Dalian Wanda and HNA have had some leeway to fix their own leverage problems. Others like Fosun’s Guo Guangchang or Geely boss Li Shufu are still striking deals, while property and technology magnates have generally steered clear of trouble.

Ye’s trouble should nonetheless worry overseas investors and executives. As President Xi Jinping further consolidates power, it suggests that neither a tycoon’s recent actions, nor received opinion about their political exposure, are much help in judging who to do business with or to avoid.

Those who should be worried include Glencore and the Qatar Investment Authority, who have yet to complete their sale of Rosneft shares to CEFC. A failed deal could even unsettle relations between Russia and China. Still, Beijing seems to be willing to pay whatever price is necessary to keep business in line.