The Toughest Man Alive (1955)

This adventurous crime drama is set in exotic Latin America and chronicles a lawman's attempt to bust up the ring of Yankee gun-smugglers who have been supplying arms to war-torn Central America. To stop them, the American agent must masquerade as a smuggler and join the gang. Meanwhile a young revolutionary is captivated by the brave words of her leader and pretends to be a singer while she looks for smugglers to sell her the weapons her group so badly needs. The agent is doing well until the smuggler he impersonates shows up and blows his cover. Fortunately, the authorities arrive before the agent is killed.