Disabled rights activists and formal mayoral candidate Theresa Ducharme says she witnessed two Winnipeg police officers in late January use excessive force on a 36-year-old Aboriginal man, who police later charged with two counts of assaulting a police officer.

Ronald Keeper, of no fixed address was being held in custody for failure to comply with a previous court order, according to Winnipeg Remand Centre staff.

Ducharme and another witness say they saw two officers pin the man-reputed to be a chronic sniff abuser-against their police car and then throw him to the ground where they punched and kicked him.

The diminutive Metis activist related that she and four health-care aides were sitting in the common area on the seventh floor of an inner-city apartment complex, which also houses a community health clinic, when they witnessed the incident

"I'm just sick about what I saw," said Ducharme. "Somebody had to say something to stop this."

Police spokesperson Const. Bob Johnson says the force's professional standards unit is investigating Ducharme's claims.

And he noted that it appears Keeper resisted officers, who were called to the complex to deal with a complaint regarding people causing a disturbance and using intoxicants.