Bonds of mysterious Chinese energy firm CEFC crashed on Thursday amid reports that its chairman Ye Jianming had been detained, complicating its deal to buy a $9bn stake in Russian oil company Rosneft.

CEFC burst into international prominence with the announcement of its 14 per cent purchase of Rosneft, shortly after Russian president Vladimir Putin visited Beijing last summer. It had previously raised eyebrows with a splashy $1.5bn purchase of assets in the Czech Republic, coinciding with a visit of Chinese president Xi Jinping to that country and Beijing’s broader strategy to gain influence in eastern Europe. 

Mr Ye’s reported detention follows Beijing’s seizure of insurer Anbang last week. It appears to mark the extension of a crackdown on private groups’ offshore acquisitions to the company most publicly aligned with China’s geopolitical objectives.