A Sierra Leonean man was charged with scheming to sell 1,000 tons of yellowcake uranium to an undercover agent posing as a broker for Iranian buyers Thursday after he was arrested at JFK airport with the subtance hidden in his shoes and lugagge, officials said.

Patrick Campbell, 33, of Freetown, allegedly responded to an ad on a Web site from an FBI agent posing as an American broker representing Iranians interested in buying uranium, according to a criminal complaint.

Campbell agreed to sell the material – which can be developed into the enriched uranium used in nuclear weapons – and offered to present a sample of his goods to the buyer in Miami.

He claimed to represent a mining company in the African nation that sold diamonds, gold and uranium.

But Campbell’s business plan fell apart at JFK Wednesday when he was found with the substance hidden in his shoes and luggage.

“Campbell assisted the agents in removing the Uranium from beneath the inside soles of his shoes and plastic bags containing Uranium were recovered from two of Campbell’s shoes,” according to the complaint.

Agents found a contract of sale on Campbell and said that he planned to disguise the shipment by mixing it with other types of ore before delivery to an Iranian port, prosecutors said.

Campbell was arraigned in Brooklyn federal court Thursday and pleaded not guilty to the charges. He faces up to 20 years in prison and up to a $1 million fine if convicted.

The case was brought by the Southern District of Florida and Campbell will be transferred there to face the charges, officials said.

Western powers have lobbied Iran to curtail their uranium enrichment program because they fear an effort to develop a nuclear arsenal. The nation’s government has maintained that their nuclear activities are for peaceful purposes only.