Ian McPhail, the interim chairman of the Commission for Public Complaints Against the RCMP, took the rare step this week of initiating the complaint himself, rather than waiting for one from the public.
The investigation follows a report in February from the New York-based group Human Rights Watch that detailed a shocking litany of allegations against police, including claims of threats, torture and sexual assault.
Prime Minister Stephen Harper asked the commission to look into the allegations shortly after the report was released, but also urged those claiming to have been victimized to come forward on their own.
That prompted an outcry from researchers involved in compiling the report, who accused Harper of missing the point: aboriginal women and girls are often too traumatized to co-operate with police.
The RCMP has also complained that its investigative hands are tied without hearing from alleged victims or knowing who they are.
Given the concerns raised in the report, "I am satisfied there are reasonable grounds for me to initiate this complaint," McPhail said in a statement released Wednesday.
Human Rights Watch researchers visited 10 communities in northern B.C. last summer, where they documented accounts from aboriginal women of how they were allegedly mistreated by police.
The communities are connected to B.C.'s Highway 16, the so-called "Highway of Tears," a notorious stretch of road where a number of women have disappeared.
The commission will examine how Mounties in those communities use force, and how they police public intoxication, conduct searches and handle reports of missing persons and domestic violence.
And the investigation could be broadened, depending on what evidence is found, and whether other complainants come forward, said the commission.
"The commission is cognizant that the potential exists that specific complaints from individuals will arise during the course of the public interest investigation," it said.
"If such complaints arise, they will be handled by the commission as separate public complaints, and/or notified to the appropriate criminal process."
Human Rights Watch, the Assembly of First Nations and federal opposition parties have for months called for a national commission of inquiry into the allegations.
The Conservative government responded by offering up a special parliamentary committee to study missing and murdered aboriginal women in Canada.
Harper, who took part Thursday in a question-and-answer session in New York hosted by the Council on Foreign Relations, was asked whether he would support an inquiry.
"I tend to remain skeptical of commissions of inquiry generally," Harper said. "My experience has been they almost always run way over time, way over budget and often the recommendations prove to be of limited utility."
Harper said the issue has been studied extensively, and that "it is time to pass to action." The government, he said, has invested resources to establish prevention programs and to buttress the investigative powers of police.
Of the roughly 2,500 files the RCMP complaints commission handles each year, between 5 and 10 are so-called "chair-initiated" complaints.
The commission can launch a public interest investigation when it sees enough evidence to conduct a probe itself, rather than handing a file over to police.
The vast majority of complaints handled by the commission are turned over to the Mounties themselves for investigation, and the commission simply reviews the results.
One of the more high-profile public interest investigations carried out by the commission recently was a probe of police misconduct complaints filed after the G8-G20 meetings held in Toronto in June 2010.