A Rio Tinto executive asked a direct report to limit the flow of information about the troubled expansion of a copper project at a time when the miner was being accused of withholding details from investors about a multibillion-dollar cost blowout and long delays with the development.

The request for less information by Rio’s former global head of major projects, David Joyce, was sent by text message to a subordinate in 2019 and has emerged as evidence in a lawsuit brought by investors, who allege they lost money because the company was slow in disclosing the issues.