SALT LAKE CITY — A federal judge has set a trial date for Washakie Renewable Energy CEO Jacob Kingston, his brother and a business partner.

In an order signed Tuesday, U.S. District Court Judge Jill Parrish scheduled a five-week trial beginning in February for Jacob Kingston, Isaiah Kingston and Lev Dermen. She also denied a request by Dermen to be released from jail ahead of trial.

The three are accused by the federal government in a half-billion dollar fraud scheme tied to Washakie Renewable Energy and renewable fuel tax credits from the Internal Revenue Service. The U.S. Department of Justice alleges the Kingstons bilked taxpayers out of $511 million in tax credits, but the overall scheme intended to amass more than a billion dollars.

The case stems from a 2016 IRS raid by the IRS on businesses tied to the Kingston polygamous family. In civil lawsuits against Jacob Kingston, lawyers have claimed Washakie produced no biofuels.

A 2016 investigation by FOX 13 found Washakie Renewable Energy was a big player on Utah’s Capitol Hill, making numerous political contributions to lawmakers as well as the governor, attorney general and Utah Republican Party. The company also advertised heavily at Utah Jazz games and Megaplex movie theaters.

The case has raised some interesting connections between the Kingstons, who are prominent members of one of Utah’s largest fundamentalist Mormon churches, and Turkish political leaders. Photos published in Turkish news media last year showed Jacob Kingston meeting with President Recep Tayyip Erdoğan when he was pitching business investments in that country.

The feds have also accused the Kingstons and Dermen of stashing millions in bank accounts in Turkey and planning to flee there to avoid prosecution. All three men have denied those accusations and pleaded not guilty to fraud and money laundering charges.