In a similar study by the same team in 2007, 67 percent of U.S. bills were found to be tainted with cocaine. The new study puts the percentage at 85 to 95—a jump of roughly 20 percent, Zuo said.

They located a red straw with white powder residue, two folded dollar bills ... Officers said the dollar containing the cocaine had an aggregate weight of 1.24 grams.

U.S. Customs and Border Protection (CBP) officers confiscated 12.2 kilograms (27 pounds) of cocaine concealed within a hidden compartment in a motorized wheelchair at George Bush Intercontinental ...