TORONTO - Ontario's police watchdog says it will start collecting data on race as part of its investigations this fall, but only on a voluntary basis.

The Special Investigations Unit says it will collect the information from complainants -- those who have been seriously injured or who allege sexual assault, or relatives of those who have died.

The agency says it will also collect data from officers under investigation.

The change is set to begin Oct. 1.

The move was announced as the Ontario Human Rights Commission released a second report that found Black people in Toronto are "disproportionately" arrested, charged and subjected to use of force by the city's police service.

The document released Monday found that even though Black people represent only about 8.8 per cent of the city's population, they represented almost a third of all charges in police data from 2013 to 2017.