The Alberta Energy Regulator says it will launch an independent investigation into the tailings leak at Imperial Oil's Kearl oilsands mine.
The regulator says in a news release today it is looking for a qualified, impartial third party to conduct the probe.
It says the inquiry will relate to issues around notification of the spill and what it calls "other potential process issues."
It says the review's findings will be released to the public.
Last May, Imperial reported discoloured water outside one of its tailings ponds and failed to keep area First Nations apprised of the ongoing investigation.
The seepage wasn't reported until nine months later, after another 5.3 million litres of tailings escaped from a containment pond.
First Nations and the federal, Alberta and Northwest Territories governments have expressed varying degrees of concern and anger about the slow notification.
The regulator's release does not discuss the timeline and says it will not comment further.