The officers unsealed the greeting card, which bore the images of four-leaf clovers and the word "success" repeated three times, and discovered a tan powder that itself had been laminated and sandwiched between pieces of cardboard inside the card.
The 8 grams of powder tested positive for heroin, Customs said. The street value of the drugs was estimated at about $500.
"This heroin interception is another example of how Customs and Border Protection officers exercise vigilance to deftly uncover creative narcotics concealment methods. CBP officers' border enforcement mission and inspections expertise helps to keep our communities safe," said Kevin Donohue, acting CBP port director for the Area Port of Philadelphia.
No arrests were made and the investigation was ongoing.
