WASHINGTON — Investigators from Wright-Patterson Air Force Base helped resolve a case in which a defense contractor agreed to pay the U.S. government $1.95 million to settle charges the company improperly billed the government for work under a military aircraft engine contract.

The U.S. Department of Justice announced the settlement by CDI Corp., a Philadelphia-based company with a regional office in the Cincinnati suburb of Sharonville, near General Electric Co.’s aircraft engine plant in Evendale. Agents of the Air Force Office of Special Investigations at Wright-Patterson investigated the case, with audit support from the Defense Contract Audit Agency. The Justice Department negotiated the settlement.

Federal authorities said CDI Corp. billed the military for work that was not actually performed. The government followed up on a whistle-blower lawsuit filed by a former CDI employee who claimed that CDI wrongfully charged labor costs to work orders from 2001 through 2006 under a military engine contract on which GE was the prime contractor.

CDI said it did not admit to any wrongdoing in reaching the settlement.

“We have taken appropriate steps to improve the billing processes that were in place in the 2001-2006 period to ensure that problems like this are unlikely to occur again,” company spokesman Vincent Webb said in an e-mail statement Monday.

Former CDI employee Vicki Lanich filed the whistle-blower lawsuit in Cincinnati federal court under the False Claims Act, a U.S. law which allows citizens to file lawsuits in behalf of the government if they believe the government has been cheated. The law allows the government to take over handling of the case, and the whistle-blower can receive a portion of any money recovered. In this case, Lanich will receive $360,750, the Justice Department said.