The Mounties say they received a complaint from a patient who had concerns about the treatment he received.
Police say an investigation revealed the supposed doctor had no medical licence but had treated people — often in their homes — in Winnipeg, Steinbach, Brandon, Selkirk and other areas.
This week, RCMP in Steinbach arrested Leslie Colmer, who is 66.
He faces 14 charges of fraud and one of assault, and is being kept in custody pending a court appearance.
RCMP spokeswoman Tara Seel will not go into details about the allegations, but says the investigation continues and further charges may be possible.