China’s richest man, an electronics tycoon worth more than £4 billion, has disappeared, amid reports that he is under investigation for alleged insider trading.

Huang Guangyu, 39, who turned a single street stall selling radios and watches into China’s largest electrical appliance chain, has not been heard of for several days, according to his company. Mr Huang vanished last Wednesday and the absence of information about his fate highlights the opacity of China’s justice system and the secrecy with which the police routinely conduct their investigations.