The Canadian ship HMCS Whitehorse helped intercept more than 5,200 kilograms of cocaine of the coast of Costa Rica, the Department of National Defence says.

The three-day operation took part in March, DND said in a news release. It wasn’t announced until Thursday evening to "avoid jeopardizing the investigation."

The U.S. Coast Guard and U.S. Navy asked for the Canadian military’s help after seeing the crew of a freighter "throwing bales of contraband overboard," the release said.

Crews searched the suspect ship and didn’t find any more drugs on board, but hauled about 5,284 kilos of cocaine out of the sea.

The narcotics interception was the second-largest seizure in the history of Operation Caribbe — the Canadian Armed Forces’ contribution to an international effort to prevent drug trafficking in the Caribbean, the eastern Pacific Ocean and in the waters off Central America. The largest was in 2011, when the HMCS St. John’s helped the U.S. Coast Guard seize 6,750 kilos of cocaine, the release said.

Defence Minister Jason Kenney praised the crew of the HMCS Whitehorse "for their work in stopping this massive shipment of illegal drugs from entering our communities."