Trading in shares of China Evergrande was suspended on Thursday after a media report that its chairman had been placed under police surveillance on the mainland.

The report fuelled concerns over the developer's future as it struggles with a growing threat of liquidation. Trading in two other Evergrande units, in property services and electric cars, was also suspended.

Each company filed a one-line trading halt notice with the Hong Kong stock exchange before the market opened on Thursday morning, saying that the suspension would take effect at 9am. They gave no reason for the suspension.

China Evergrande shares closed at 32 cents per share on Wednesday. They resumed trading last month after being suspended for 17 months.

Bloomberg News reported on Wednesday that Evergrande's chairman and founder, Hui Ka Yan, had been placed under police monitoring at a designated location. Other agencies say they've been unable to verify the reports.

In a stock exchange announcement on Sunday, the group said it would be unable to issue new notes as part of a restructuring of its overseas debt because one of its subsidiaries, Hengda Real Estate, is under investigation.