The Department of National Defence says a Canadian naval vessel was part of a large drug bust last month in the eastern Pacific Ocean off the coast of Costa Rica.

HMCS Whitehorse, working with the U.S. Coast Guard and U.S. Navy, intercepted more than 5,200 kilograms of cocaine in international waters from a coastal freighter.

National Defence says the crew of the freighter began throwing bales overboard when a patrolling U.S. Navy vessel approached.

The Whitehorse and a U.S. Coast Guard cutter were called in to join the operation, which lasted three days.

A boarding party did not find any additional drugs on board the freighter after bales containing more than 5,200 kilograms of cocaine were retrieved from the sea.

National Defence says the seizure could not be divulged until now to avoid jeopardizing the investigation into the matter.

HMCS Whitehorse is part of Canada's contribution to a multinational effort to prevent drug trafficking in the Caribbean basin, the eastern Pacific and the waters of Central America.