The massive cash flown out of Afghanistan includes some diverted Western aid, according to preliminary evidence gathered by Afghan and U.S. investigators.

U.S. and Afghan officials raided Jan. 14 the New Ansari Exchange, Afghanistan’s largest “hawala” money-transfer business.

“Hawalas” like New Ansari move money globally through a network of dealers. A customer in one part of the world, say Kabul, might give money to a local hawala for someone in another country like Dubai, for example. Within minutes, the recipient can walk into a hawala in Dubai and get the cash.

The raid also collected documents that link prominent Afghan businessmen and politicians, including relatives of President Hamid Karzai, in the movement of some USD3.65 billion flown out of the Asian nation annually.

While some of the money came from legitimate businesses, some was sourced from diverted Western aid and logistics money, opium profits, and Taliban funds, according to U.S. and Afghan investigators.

New Ansari was helping to launder money gained from illicit opium trade, and Taliban extortion and drug trafficking, according to the U.S. and Afghan officials.

The New Ansari investigation may put a damper on U.S.-Afghan relations. The situation is “a real reality check” for the U.S. and its European allies,” one of the U.S. officials said. The U.S. has publicly supported Karzai in recent months.

Karzai last week ordered a handpicked commission to review past and current anticorruption inquests, including the Sensitive Investigative Unit, which staged the New Ansari raid, and another U.S.-supported group, the Major Crimes Task Force, The Wall Street Journal reports.

U.S. Special Representative for Afghanistan and Pakistan Richard Holbrooke earlier said the billions of dollars in cash flown out of Afghanistan does not include U.S. aid money.

“We’re not missing money,” the U.S. special representative for Afghanistan and Pakistan said July 28 at a hearing of the House appropriations subcommittee on state and foreign operations.