A couple tried to smuggle nearly $5 million in counterfeit cash into the U.S., officials said.
Authorities stopped the pair after they arrived at Detroit Metropolitan Airport aboard a flight from Seoul, South Korea, on Friday.
U.S. Customs and Border Protection found 93 bundles of counterfeit U.S. $100 bills and 32 bundles of counterfeit Vietnamese dong in their luggage.
The $4.65 million recovered was so-called "Hell money" — which is printed on joss paper and burned as an offering to the dead in some Asian cultures.
"Attempting to import any amount of counterfeit currency, regardless of the intended purpose, can have serious implications for arriving travelers," CBP port director Devin Chamberlain said.
The bogus bucks were seized by agents from Homeland Security Investigations and the U.S. Secret Service.