A man from Sierra Leone has been arrested by government investigators smuggling uranium in his shoes.

Patrick Campbell has been charged with attempting to broker a sale of 1,000 tons of yellowcake uranium to the Iranians. He had samples of the uranium hidden inside his shoes.

Campbell believed he was meeting with Iranian officials who were really undercover U.S. agents.

Yellowcake uranium can be enriched to create nuclear fuel and weapons.

Campbell responded to an ad placed on a website seeking to purchase uranium by a U.S. agent posing as an American broker for Iran. If convicted, Campbell faces up to 20 years in prison and a $1 million fine.