VANCOUVER — The British Columbia Supreme Court trial of a former RCMP officer accused of a security offence by working for China has heard testimony describing how three Chinese police officials went "missing" for six hours during an RCMP-escorted visit to Vancouver in 2018, setting off concerns they could be trying to illicitly repatriate someone. RCMP Supt. Peter Tsui told the trial of William Majcher, who is charged under Canada's Security of Information Act, that the officers with the Chinese Ministry of Public Security were part of a delegation being "hosted" by Canadian police as they travelled to Vancouver and…