The chairman of Hong Kong's Mercantile Exchange is under police investigation, the government said on Friday, as three other men were charged with possessing false documents including a fake cheque for $460 million following a probe into alleged irregularities at the shuttered exchange, Reuters reported. Barry Cheung, the exchange's controlling shareholder and a close ally of Hong Kong leader Leung Chun-ying, resigned from all of his public posts on Friday on the grounds that he is under police investigation, a government statement said. Police said they met with Cheung on Friday but he was not arrested. -- SPA 20:24 LOCAL TIME 17:24 GMT تغريد