Alfred Baillargeon displays his swollen, bruised arm, which he said wasn't that way before he was put into RCMP custody last week. (CBC)

A Yellowknife family is accusing the RCMP of police brutality in a recent incident involving their 74-year-old father.

Family members of Alfred Baillargeon acknowledge he was drunk when police picked him up last week, but they said there was evidence that officers roughed Baillargeon up while he was in custody.

"Why did they do that? That's the answer I want," Beatrice Sangris, Baillargeon's daughter, told CBC News.

"You know, it makes me want to cry."

Baillargeon told CBC News he woke up in a police holding cell wearing only his underwear and a T-shirt, his right arm so swollen and bruised that he couldn't move it.

Speaking in the Tlicho language, Baillargeon said he could not remember how he was injured, but he said he didn't have those injuries before he went into custody.

"I want everybody to know how they treat native people in the police force, and I don't know why nobody talks about it," Baillargeon said through an interpreter, son-in-law Edward Sangris.

"A robber or a murderer, I can see it, I could see them do that. But being an elder walking down the street ... that should never happen, what they did to me."

One witness who was too afraid to speak publicly against the RCMP told CBC News that Baillargeon did not resist arrest, but was just standing there with his hands cuffed behind his back.

The witness said he saw the officer bend over, pick Baillargeon up by the ankles and throw him into the police vehicle.

RCMP Sgt. Larry O'Brien would not comment on Baillergeon's case, except to say a complaint has been filed against the police force.

"That complaint will go to the Public Complaints Commission Against the RCMP. They will appoint an investigator, and the matter will be investigated fully at that time," O'Brien said late Thursday.

The investigation will include surveillance tapes from the RCMP cell Baillargeon was detained in.