— A federal grand jury has returned indictments on 21 suspects who have been named in a multi-state ring that conspired to steal used cooking oil, store it in a Durham warehouse and then sell the product known as "yellow grease," officials said.

U.S. Attorney Robert Higdon Jr. announced in a written statement Thursday that nearly two dozen suspects were indicted on conspiracy to commit interstate transportation of stolen good and money laundering.

"Used cooking oil has become a sought-after commodity by biodiesel companies, and restaurants use the sale of this oil as another source of revenue,” said John Eisert, Acting Special Agent in Charge of Homeland Security Investigations in Charlotte. “This team of co-conspirators had an elaborate scheme to steal thousands of gallons of cooking oil for their own profit in violation of several U.S. laws.”

Those suspects were identified as Kelvin Fe Arellano-Valencia, 19, of Raleigh; Samuel Cruz, 42, of Durham, Miguel Gutierrez, 24; Jaime Labra-Tovar, 23 and Ryan Mercado-Rodriguez, 24, all of Henderson; Hasan Ozvatan, 40, of Turkey; George Luis Morales, 21, of New York; Eric Evo, 24, of Richmond, Virginia; Juan Lopez-Posada, 40, of El Salvador; and Salvador Escalante, 43; Ruth Nava-Abarca, 29, Florentino Valencia-Tepoz, 47, Gregorio Vazquez-Castillo, 43; Juan de la Cruz-Gonzalez, 32; Oscar Ugalde-Escalante, 31; Emilio Gomez-Gonzalez, 36, Juan Maldonad-Hernandez, 28; Toribio Escalante-Campos, 59; Rene Espinoza-Torres, 45; Demetrio Valencia-Flores, 42, Alvaro Mendez-Flores, 38, all of Mexico.

Investigators said the suspects allegedly transported the stolen used cooking oil in box trucks to the Durham warehouse, where it was consolidated and stored.

A tanker trailer was then used to transport the used cooking oil to Virginia and elsewhere to be resold.

Investigators said six of the suspects, Juan de la Cruz-Gonzalez, Rene Espinoza-Torres, Emilio Gomez-Gonzalez, Juan Maldonado-Hernandez, Ruth Nava-Abarca and Hasan Ozvatan were fugitives and were being sought by law enforcement officers.

The indictments could shed new light on the role that spent cooking oil is playing in fueling a lucrative criminal enterprise.

According to Higdon, used cooking oil that is collected in bulk from restaurants, and represents an annual loss of $45 to $75 million, has become a valuable commodity over the past decade because of the myriad ways it can be repurposed.

Investigators said the oil, once it has been recycled, can be used for:

Biofuel.

As a nutritional addititive to animal feed and pet food.

The production of other consumer and industrial products.

Legitimate businesses will collect the used cooking oil from restaurants in exchange for compensation and then sell it to refineries so it can be processed and recycled.

If convicted, several of the suspects could each face a prison sentence of up to 25 years and a $500,000 fine.

Investigators said Gomez-Gonzalez was charged with failure to register with immigration officials, while Nava-Abarca, Valencia-Tepoz, Escalante-Campos, Ibarra-Escalante and Vazquez-Castillo were charged with alien harboring, investigators said.