Investigators with an international environmental watchdog have recommended a probe into whether Canada is violating its own laws by not stopping toxic wastewater from being dumped into the ocean along its Pacific coast.

The investigative arm of the Commission for Environmental Cooperation, created by the U.S.-Canada-Mexico trade agreement, has concluded there’s evidence Canada is failing to stop the release of millions of tonnes of contaminated water from fuel scrubbers, despite laws that are supposed to prevent it.