RICHLAND, Wash. (AP) — The U.S. Justice Department is accusing Lockheed Martin Corp. of using false records and making false statements to bill the Energy Department for tens of millions of dollars in unauthorized profits and fees at the Hanford Nuclear Reservation.

The federal civil lawsuit was filed last week in U.S. District Court in Eastern Washington.

The lawsuit also accuses Lockheed Martin of using federal money to pay millions of dollars in kickbacks.

Hanford is now involved in a massive cleanup effort that costs more than $2 billion per year.

The lawsuit covers the period from 2010 to 2015. Lockheed Martin denied the allegations and said it will defend itself vigorously.