SAN JUAN, Puerto Rico (AP) — A federal control board overseeing Puerto Rico’s finances has filed a lawsuit to recover what it calls massive fraudulent payments made by the island’s power company to fuel suppliers for more than a decade.

The lawsuit was filed Sunday against fuel companies Trafigura and Vitol for allegedly supplying low-grade oil as well as three laboratories accused of receiving money for falsifying tests on oil bought by Puerto Rico’s Electric Power Authority.

The board said billions of dollars in alleged overpayments from 2002 to 2015 caused the power company to slide deeper into debt.

Power company spokeswoman Edith Seda said no one was available for comment. Trafigura and Vitol did not immediately return messages for comment.

The power company has denied any wrongdoing in a related case.