The man had successfully cleared the customs and immigration and a search of his bags did not yield anything, police said.

BBC: Sri Lankan arrested in India with diamonds in stomach

Now they insist that their procedures and intelligence have led to tightening up of controls, with better international cooperation, encouraged by the World Customs Union, and X-ray scanners to search cargo.

BBC: Lab bids to combat species smuggling

American agents notified Mexican authorities to search their side of the border, U.S. Customs and Border Protection said in a statement last December.

CNN: Mexican police nab drug-launching cannon near border