Chinese entrepreneur Li Hejun has offered to personally guarantee payment of the HK$3.2bn ($466m) owed by his mainland group to its troubled Hong Kong-listed subsidiary, as part of efforts to end a near two-year trading suspension.

Mr Li shot to prominence in 2015 when the soaring value of his listed unit Hanergy Thin Film Power, a solar panel equipment maker, briefly made him China’s richest man. However, its shares have been suspended since May 2015 after they inexplicably plunged almost 50 per cent in less than half an hour, wiping $19bn off its value in the process.

The rise and fall happened amid a growing chorus of questions over the links between HTF and its parent, both of which are controlled by Mr Li, and the growing pile of receivables owed to HTF by Hanergy Holding, the parent.