The Special Inspector General for Afghanistan Reconstruction (SIGAR) also said that one of the most "troubling" issues is how the Department of Defense was unable or unwilling to explain why the "ill-conceived" project was so expensive.



"Even considering security costs associated with construction and operation in Afghanistan, this level of expenditure appears gratuitous and extreme," SIGAR said in a report issued Monday.

The agency's top official went further.

"It's an outrageous waste of money that raises suspicions that there is something more there than just stupidity," John Sopko, the special inspector general, told NBC News. "There may be fraud. There may be corruption. But I cannot currently find out more about this because of the lack of cooperation."

Despite having vast natural gas reserves, Afghanistan is heavily reliant on importing petroleum products. The Downstream Gas Utilization project — overseen by the Task Force for Stability and Business Operations (TFBSO) — was aimed at changing that.