A man has been arrested in New York City's international airport with uranium destined for Iran hidden in the soles of his shoes, the US Justice Department said.

Patrick Campbell, 33, who was arrested on Wednesday as he arrived at the John F Kennedy airport from Paris, is accused of trying to act as an intermediary to sell Iran 1,000 tonnes of purified uranium, in violation of US law.

The buyer was actually an undercover US immigration officer. Asked to supply 1,000 tonnes of uranium - disguised with other types of ore to escape detection - Campbell promised to ship the product, disguised as chromite, from Sierra Leone to the port of Bandar Abbas in Iran.

According to the criminal complaint, Campbell admitted to agents that he had engaged in talks for "a contract for the sale of uranium to be delivered to Iran".

When confronted, he also admitted that he had brought a sample of the raw uranium ore with him concealed in his luggage.

The Sierra Leone-based Campbell had been under surveillance since May 2012, when he responded to an advertisement on the site Alibaba.com by someone looking to buy uranium 308, or yellow cake.

Accused of violating US law concerning transactions with Iran, Campbell could face up to 20 years in prison and a fine of $1 million.

Al Jazeera