BUTLER TWP — A Butler Township man and his brother, who lives in Gibsonia, are among five defendants charged in a case prosecutors say centers on a “major fraud against the U.S. Department of Defense.”

Federal prosecutors in Pittsburgh announced charges against John P. Bucker, 67, of Lyndora, Thomas G. Buckner, 65, of Gibsonia this afternoon. Both have been charged with a single count of defrauding the U.S. Army Tank-Automotive and Armaments Command (TACOM), and two counts of income tax evasion.

The Buckners, who are brothers, were co-owners of Ibis Tek LLC, a Butler-based company that specializes in developing transparent armor and accessory products for tactical and combat vehicles and also has an office near Saxonburg.

The company had a subcontract with the U.S. Department of Defense to produce vehicle emergency escape window kits for Humvees. And prosecutors say the Buckners inflated the project's costs by creating a shell company called Alloy America LLC, which they used to drive up the price of Chinese-made components. Prosecutors also say the Buckners sold scrap aluminum collected throughout the manufacturing process but failed to credit the money to the government.

The government claims the alleged fraud cost the DoD more than $6 million.

The Buckners are defendants in the case alongside Harry H. Kramer, 52, of Wexford, Anthony Shaw, 55, of Rochester Hills, Mich., and David S. Buckner of Warran, Mich., who is not related to the Ibis Tek owners.

Prosecutors say Kramer has been charged for his role as Ibis Tek's chief financial officer, and for allegedly filing false returns for the company in 2009 and 2010.

Shaw, who was a civilian employee at TACOM during the alleged fraud by Ibis Tek, is charged with accepting more than $1 million in illegal gratuities and checks as well as income tax evasion for not reporting the payments, which came in 2009 and 2010.

David Buckner has been charged with impeding the Internal Revenue Service and attempting to conceal the payments to Shaw.

Prosecutors said that Thomas and John Buckner face a maximum of 20 years in prison and a fine of $1.5 million in the case.