The United States military has blacklisted Kam Air, an Afghan airline, accusing it of carrying large quanities of opium.
Kam Air is denying the accusations that it has been using civilian flights for smuggling operations.
Kam Air operates a fleet of 16 planes, including Boeing 767s and 747s, and Antonov cargo planes which fly to many destinations.
The BBC reports its only scheduled Central Asian passenger route is between Kabul - Dushanbe, the capital of Tajikistan.
The blacklisting of Kam Air first came to light in an article in the Wall Street Journal on Friday.
Airline owner Zemary Kamgar said that he was consulting his lawyers.
While he had not received written confirmation of the move against Kam Air, he said the blacklisting could also be the work of competitor companies eager for a share in transporting military equipment.
The accusations were also strongly denied by Transport Minister Daud Ali Najafi who told the BBC that security checks at Kabul international airport are very tight.
Correspondents say there is growing concern among Western countries over Afghanistan's burgeoning drug trade.
A report by the UN Office on Drugs and Crime in November said that opium production in Afghanistan had fallen by a third, but the amount of land used to cultivate the crop rose by 18%.
