Sixteen military transport planes bought by the United States government for the Afghan Air Force (AAF) at a cost of nearly $500 million were recently destroyed by the Afghan military and sold for scrap parts at around six cents per pound, prompting a government inquiry to determine why millions of taxpayer dollars were wasted on the ill-fated program.

The Department of Defense purchased for the AAF a total of 20 Italian-made G222 military transport planes at a cost of $486 million. However, the fleet was grounded in March 2013 "after sustained, serious performance, maintenance, and spare parts problems" were discovered, according to the Special Inspector General for Afghanistan Reconstruction (SIGAR).

After sitting unused for some time on the tarmac at Kabul International Airport, the Afghan military decided to destroy 16 of the planes and sell the scrap metal for roughly 6 cents per pound, according to SIGAR, which has launched an investigation to determine how such a large amount of taxpayer dollars were wasted on the fleet.

SIGAR had intended to inspect the aircraft as part of its investigation and appears to have been caught off guard by the fleet’s destruction.

"It has come to my attention that the sixteen G222s at Kabul were recently towed to the far side of the airport and scrapped by the Defense Logistics Agency," SIGAR head John Sopko wrote in a letter to the U.S. Air Force that was released on Thursday.

"I was also informed that an Afghan construction company paid approximately 6 cents a pound for the scrapped planes, which came to a total of $32,000," Sopko revealed. "I am concerned that the officials responsible for planning and executing the scrapping of the planes may not have considered other possible alternatives in order to salvage taxpayer dollars."

Sopko sent a similar letter to Secretary of Defense Chuck Hagel seeking to determine what exactly happened and what the fate of the four remaining planes will be.

SIGAR is asking that the DoD and U.S. Air Force provide it with all documentation relating to the program and the decision to destroy the planes. The four remaining G222s are currently parked at Ramstein Air Force Base in Germany.

No decision has yet been made as to whether these planes also will be destroyed and sold as scrap metal.

SIGAR’s primary concern is that officials in the United States did not consider more worthwhile options before destroying the planes for very little return on the taxpayers’ investment.

The watchdog agency is requesting copies of all documents pertaining to the decision to destroy the planes, as well as communications relating to the decision-making process.

This includes an explanation as to "whether alternatives to scrapping the planes were considered and, if alternatives were considered, why they were not pursued, such as flying the planes out of Afghanistan to the United States, Europe, or other country for sale."

SIGAR also is requesting advance notice from the DoD if it decides to destroy the four remaining planes in Germany.