Two prosecutors known for having a top-notch track record are leading the federal investigation into claims that truckstop chain Pilot Flying J bilked some trucking customers out of financial rebates from fuel purchases. Meanwhile, another lawsuit has been filed against the company.

David Lewen and Francis "Trey" Hamilton are described as “very knowledgeable and very diligent” and “top of the line” prosecutors, according to the Cleveland Plain Dealer newspaper. The 37-year-old Lewen has prosecuted complex drug crimes involving drug kingpins. The the 41-year-old Hamilton has experience in white-collar crimes.

While the U.S. Attorney’s Office that is handling the case has yet to provide any information about Lewen and Hamilton, the newspaper talked with several attorneys who gave the pair high marks. One attorney said white-collar cases and those involving drug-dealing hierarchies were similar and complex.

In mid-April, agents from the FBI and IRS served a series of search warrants on Pilot Flying J’s headquarters as well as those of some company officials. It was part of an investigation amid allegations the company concocted a scheme to boost profits by altering the amount of money it was supposed to rebate to customers.

No arrests have been made in the case. Pilot Flying J CEO Jimmy Haslam had denied any knowledge of the alleged scheme.

Since that time nearly a dozen lawsuits have been filed against Pilot Flying J. The latest one is from Mississippi and a driver who says he is a longtime customer.

The Tennessean newspaper reports the class action filed by lawyers for Mike Campbell mirrors claims in the FBI affidavit used to secure the search warrants against Pilot Flying J, as well as those in the other lawsuits. This newest litigation claims customers are owed more than $5 million.

During a recent public appearance, Haslam urged anyone who felt like they had not been treated fairly by Pilot Flying J to deal directly with the company, saying they would quickly get any money owed to them, rather than filing a lawsuit. At the same time, he denied any wrongdoing by the company.