The U.S. Agency for International Development is paying a charter airline in Afghanistan $14 million a year for flights that its employees never took, a new audit reveals.

The no-show passengers increased costs to the U.S. government even as the development agency spends billions of dollars to rebuild Afghanistan’s roads, schools and other infrastructure after decades of war and neglect, the USAID’s inspector general found.

“No-show passengers obligate the contractor to operate aircraft with empty seats and impede the efficiency of the [agency’s] portion of the Embassy Air program,” David Thomanek, the acting Afghanistan Director of the Inspector General’s office wrote in the report released last week.

The $14 million sum represents 20 percent of the agency’s annual contract with Aircraft Charter Solutions, Inc. to fly USAID workers and cargo to remote locations in Afghanistan, where provincial reconstruction teams and other U.S. government development programs are buildings roads and other infrastructure.

The audit drew a strong rebuke from Sen. Susan Collins (R-Maine) ranking member of the Homeland Security and Governmental Affairs Committee.

“While USAID is wasting $14 million annually to fly empty seats to Afghanistan, critical programs to train police, build schools and promote maternal and child health are left without proper support and oversight,” Collins said in a statement.

The audit said the charter company is paid the same, whether all seats on a plane are occupied or the plane is half full. The seats reserved for no-show passengers could have been made available to other passengers, smaller aircraft could have been used if no-shows had canceled their reservations, and in a few cases flights could have been canceled entirely, auditors found.

The inspector general recommends that the development agency implement a small penalty fee of $50 to $100 for every no-show, to be reimbursed by the employee.

But USAID officials, in a written response to auditors, said up to half the no-shows are due to security restrictions that are beyond the control of the passengers. Robert Hellyer, the acting mission director for Afghanistan, said it would not impose charges on no-shows. Instead, Hellyer said his office would track them down, “identify trends and recommend corrective action in cases of abuse.”

Auditors disputed whether half of the no-shows are waylaid by security restrictions, saying the number is much lower.