While corruption by Afghan government officials here in Kabul has been widely condemned, corruption by Western officials in Afghanistan has received little if any scrutiny. In his report to President Obama, as leaked to the Washington Post last week, General Stanley McChrystal repeatedly referred to “widespread corruption” in Afghanistan’s government. He also alluded, more delicately, to the “perception of corruption” within the international community and the military.

But there may be more than just “perception,” especially in light of an affidavit signed in August by a federal criminal investigator, who said he is probing “contract steering on USAID-funded contracts in Afghanistan.”

A federal arrest warrant was quietly issued last month for a former official employed by the major US government reconstruction contractor here in Afghanistan, in a case that underscores the lure of potential contract fraud in Afghanistan. Scott “Max” Anthony Walker was a “security coordinator” for the $1.4 billion infrastructure program commissioned by US Agency for International Development and funded by US taxpayers. The program, which builds power plants and roads, is run by a joint venture of American construction conglomerates Louis Berger Group and Black & Veach. The 36-year-old Australian named in the arrest warrant worked for Black & Veach, and he allegedly tried to obtain a kickback–apparently of a quarter-of-a-million dollars–from private military companies looking for a piece of business of protecting the reconstruction effort.

In the affidavit, the investigator alleged that Walker had claimed that he and a colleague “were willing to vote to steer the subcontract to whichever vendor paid them $250,000 (USD) at a minimum.” He allegedly told a co-conspirator, whom he met “socially at a Kabul bar,” that the subcontract was worth $55 million.

USAID investigators first learned of the kickback, according to the affidavit, when they were notified by Louis Berger Group itself. Prosecutors announced last month that Bryan Lee Burrows, who worked for another company, had pleaded guilty, but the involvement of an official from the main USAID contractor hasn’t been reported.

Another alleged coconspirator, Ryan Scott McMonigle, was arrested last month in the case.

Walker himself could not be reached for comment. The affidavit in the case said he left Afghanistan for Australia in May.