OTTAWA — In defiance of a House of Commons committee, the president of the Public Health Agency of Canada still won’t explain why two government scientists were fired 18 months after being escorted from Canada’s highest−security laboratory. Iain Stewart had been given a deadline of Friday to provide an explanation to members of the special committee on Canada−China relations for why PHAC terminated the employment of Xiangguo Qiu and her husband, Keding Cheng, in January. Instead, he sent the MPs a letter saying that the Privacy Act does not allow him to share “employment or labour−relations matters concerning public servants.” Questions about an RCMP investigation into the two Canadian government scientists should be directed to the Mounties, Stewart added. The pair were escorted out of the National Microbiology Laboratory (NML) in July 2019 over what was described at the time as a possible policy breach and administrative matter. In his …