The unimpeded “bulk cash flows raise the risk of money laundering and bulk cash smuggling — tools often used to finance terrorist, narcotics and other illicit operations,” the report said. The cash, and now the gold, is most often taken to Dubai, where officials are known for asking few questions. Many wealthy Afghans park their money and families in the emirate, and gold dealers say more middle-class Afghans are sending money and gold — seen as a safeguard against economic ruin — to Dubai as talk of a postwar economic collapse grows louder.

But given Dubai’s reputation as a haven for laundered money, an Afghan official said that the “obvious suspicion” is that at least some of the apparent growth in gold shipments to Dubai is tied to the myriad illicit activities — opium smuggling, corruption, Taliban taxation schemes — that have come to define Afghanistan’s economy.

There are also indications that Iran could be dipping into the Afghan gold trade. It is already buying up dollars and euros here to circumvent American and European sanctions, and it may be using gold for the same purpose.

Yahya, a dealer in Kabul, said other gold traders were helping Iran buy the precious metal here. Payment was being made in oil or with Iranian rials, which readily circulate in western Afghanistan. The Afghan dealers are then taking it to Dubai, where the gold is sold for dollars. The money is then moved to China, where it was used to buy needed goods or simply funneled back to Iran, said Yahya, who like many Afghans uses a single name.

He declined to name those involved in aiding Iran. But Western officials said his description of how the process worked tracked with their knowledge of money laundering networks that operate in Afghanistan and the surrounding region.

Before officials can say whether the gold shipments are part of an illicit financial scheme, though, they first have to figure out how much gold is going out — or, for that matter, coming in.

It is a task easier said than done. The Finance Ministry, which is supposed to collect taxes on each shipment, did not have figures, said Wahidullah Tawhidi, a spokesman for the ministry. He suggested that the Commerce Ministry would know. The Commerce Ministry did not, and officials there said it would be best to contact airport customs officials.