A Toronto-area man has been charged following a human trafficking investigation in Calgary, and investigators believe there may be additional victims.The Alberta Law Enforcement Response Teams (ALERT) said its human trafficking team began investigating after receiving a tip about a man allegedly involved in human trafficking in the Calgary area and exploiting a vulnerable woman.Investigators gathered intelligence that led to a quick arrest, the agency said.Mark Williams, 42, of Scarborough, Ont., was arrested on Friday in northeast Calgary’s Sunridge neighbourhood. He is charged with procuring a person for sexual services.Williams remains in custody and is scheduled to appear in court on Thursday.The victim has been connected with support resources, according to ALERT. The agency notes that survivors of human trafficking can access help by calling 211.Investigators believe there may be additional victims and are asking anyone with information to contact police or Crime Stoppers at 1-800-222-8477.