The Canada Border Services Agency says the contents of the 12-metre refrigerated container were X-rayed with a high-energy screening system.
When officers noticed inconsistencies in the X-ray image and the container, it was offloaded and examined further.
Officers also saw irregularities in the ceiling of the container, where 109 bricks containing an unknown substance were found attached to the roof.
Lab tests later confirmed it was cocaine.
Border Services officials are continuing the investigation into the seizure.