In Xi Jinping’s China, people go missing all the time as the ruling Communist party routinely rounds up the powerful and the meek alike on often vague and politically motivated charges.

But the mysterious disappearance — and subsequent reappearance this week — of billionaire Guo Guangchang at the behest of still unidentified authorities was anything but routine, suggesting that private sector tycoons were being targeted by the Chinese president’s anti-corruption campaign.

Unlike counterparts in state-owned enterprises, China’s richest private business people have so far avoided the brunt of Mr Xi’s three-year anti-graft drive and a more recent investigation into the summer meltdown on the Shanghai and Shenzhen stock exchanges. Though Mr Guo has not been accused of any wrongdoing, the suggestion that party and government investigators might be turning their attention to the private sector has shocked the country’s business and investment community.