Beginning this week, Xe Services, formerly known as Blackwater, will defend themselves against accusations they overbilled the State Department on a $1 billion contract for services in Iraq and Afghanistan.

In 2008 former employees Brad and Melan Davis brought a whistleblower lawsuit alleging the company falsified records stating the number of Blackwater employees stationed in Iraq and Afghanistan and reported exaggerated travel expenses. The company is alleged to have defrauded the government for more than $123 million, Melan Davis claims to have intimate knowledge of the alleged fraud in her capacity gathering travel expense reports for State Department submission.

However, U.S. District Judge T.S. Ellis III has already dismissed several claims, such as accusations that Blackwater charged the State Department for prostitutes and that the company overbilled on a security contract in post-Katrina Louisiana. The trial is expected to last two weeks.