Government auditors are questioning an argument–regarding decreased risk of having counterfeit parts–in favor of the Pentagon buying helicopters from a controversial Russian firm.

The Government Accountability Office (GAO) released a report yesterday on its review of the Pentagon’s purchase of Mi-17 helicopters, for use by the Afghan military, through Russia’s Rosoboronexport. The Russian state-controlled arms exporting company has been criticized for supplying arms to Syria that the embattled government turned on its own civilians.

U.S. lawmakers including Sen. John Cornyn (R-Texas) have been pressing the Pentagon to stop purchasing the helicopters through a non-competitive contact with Rosoboronexport. They are concerned the Pentagon will buy a fresh batch of Mi-17s through it, despite their attempts to block such a deal in legislation including the fiscal year 2013 defense authorization act.

The GAO says in its new report–which the Senate Armed Services Committee (SASC) requested–that it found “no evidence” that buying the Mi-17s through Rosoboronexport instead of another vendor would decrease the risk of counterfeit parts ending up in the aircraft.

The auditors’ wide-reaching “performance audit” assessed the Pentagon’s 2012 cancellation of a competitive solicitation for 21 Mi-17s–which happened after Russian authorities said they would sell the helicopters only through Rosoboronexport–and the United States’ evaluation of alternative procurement approaches. The GAO also examined how the Pentagon’s practice of contracting directly with Rosoboronexport could impact counterfeiting and related safety issues. 

“(The Department of Defense) DoD determined that the Rosoboronexport contract offered the Army greater access to technical information from the original equipment manufacturer and increased assurance of safety compared to previous Mi-17 contracts,” the GAO says in a letter accompanying its new report. “However, the risk of counterfeiting may be similar.”

The GAO goes on to say the Pentagon’s 2011 contract with Rosoboronexport “provided Army officials with extensive access to the original equipment manufacturer’s facilities and allowed for technical discussions on the aircraft’s design, testing, and manufacturing processes.” It says this “level of insight enabled the Army to determine that the Russians’ process was sufficient by U.S. standards to certify airworthiness.”

Yet, the GAO adds: “However, both Rosoboronexport and other vendors have purchased new Mi-17s that came from the original equipment manufacturer–a practice used to decrease the risk of counterfeiting. Therefore, we found no evidence that shows how Rosoboronexport would decrease the risk of counterfeit parts over other vendors if aircraft were purchased new from the original equipment manufacturer.”

The GAO report examines how the Office of the Secretary of Defense directed the Navy to cancel its competitive solicitation for 21 civilian Mi-17s. That happened after Russian officials said in 2010 that in accordance with Russian law they would only sell the helicopters only through Rosoboronexport, because they were intended for military use by the Afghans.

The Pentagon did not assess other ways to buy Mi-17s after verifying that Russia would sell the helicopters to the United States only through Rosoboronexport, according to the GAO.

“The Navy’s original procurement strategy in 2010 was to purchase civilian Mi-17s and subsequently add weapons to them for use in Afghanistan,” the GAO letter says. “However, given the Russian government’s determination, DoD officials stated that no alternative approaches to procure the helicopters were available to them as any attempt to procure a new civilian aircraft could be blocked by Rosoboronexport if DoD did not go through them, and purchasing used helicopters posed safety concerns.”

Though some potential U.S. vendors have said they could provide the Mi-17s to the Pentagon at a lower cost, “an Army analysis determined that the price paid to Rosoboronexport for the Mi-17s was reasonable and fell within the historical range of the unit price paid for similar aircraft,” the GAO says.