Authorities in New York say they have smashed a big cigarette smuggling ring and have arrested 15 people of Palestinian origin.
They say some of those people may have links to Islamic militant groups.
The state's attorney general said investigators had recovered only "a fraction" of the proceeds from sales of more than a million untaxed cartons, the BBC reports.
The scheme has cost the state an estimated $US80 million in tax revenue, say officials.
Officials have not linked the proceeds of the cigarette sales to any militant fund-raising, but say they will keep pursuing the missing money.
"This dangerous criminal ring was able to generate astounding profits that we are still continuing to trace," said New York Attorney General Eric Schneiderman in a statement.