Ottawa, Jun 4 (IANS): Former Canadian Senator Murray Sinclair has called for an independent investigation into the sites of indigenous residential schools across the country.

Addressing the the Indigenous and Northern Affairs Committee of Parliament on Thursday, Sinclair, also the Chair of the Truth and Reconciliation Commission (TRC), said a search must be conducted outside the purview of a government department, reports xinhua news agency.

"In order for us to deal with this properly, we need to ensure that there is an independent study that is done into that question of those burial sites, where they are, and what the numbers are going to tell us," he told the committee.

On May 28, the Tk'emlups te Secwepemc First Nation confirmed the discovery of the remains of 215 indigenous children buried at the site of the former Kamloops Indian Residential School, which operated between 1890 and 1978.

It had housed as many as 500 children at its peak.

Over the course of more than 100 years, some 150,000 indigenous children were taken away from their families and forced to attend the church-run residential schools, where many suffered physical and sexual abuse, malnutrition, and neglect.

More than 4,000 are believed to have died.

Following the discovery, indigenous leaders, residential school survivors, and opposition parties have called for the government to fund the research and excavation of all sites of former residential schools for unmarked graves in the country.

Sinclair said he has spoken with "about 200 survivors" over the course of the last few days, who have expressed their "grief, their feelings of anger, their feelings of frustration" over the situation.

The government has been criticized for failing to fully implement all sections of the 2015 TRC report with calls to address the missing children and unmarked graves at residential schools.

The report includes maps showing the location of deceased residential school children; appropriate ceremonies, markers, and reburials; procedures for the ongoing identification, documentation, maintenance, commemoration, and protection of residential school cemeteries or other sites at which residential school children were buried.

Sinclair, who is also an indigenous lawyer, said the independent probe should be "overseen by a parliamentary committee that will ensure that it's done in a proper way as opposed to having anyone within the justice department or the department of Indigenous affairs controlling the process".

"They're now beginning to question those who have made this story available and unfortunately, in a typically heavy-handed and ham-handed police way, they are simply intimidating people, rather than helping them," he added.