The FBI agent reported Mitchell deposited the check in 2009.
FBI agents reported interviewing Ross in October 2011, a source told The Oklahoman. The agents reported Ross was with the Tulsa professional arena football team.
The agents reported Ross acknowledged gambling online and writing checks to cover his losses, the source said.
Ross is an entrepreneur who has been involved in a number of businesses. He said he currently runs a small, private investment company and lives in Arizona.
In the interview Wednesday with The Oklahoman, Ross said he wrote maybe four or five checks to Mitchell in 2009 and 2010 and received one from Mitchell.
“The FBI said, ‘You guys aren't very good at this …' I said, ‘Absolutely. We were terrible.' I had a buddy who thought he was good on baseball and I was along for the ride,” Ross said.
He said he may have seen Mitchell one time when Mitchell delivered cases of energy drinks to the Tulsa Talons.
A federal grand jury in September indicted Mitchell, two of his sons, six other men and a Costa Rican company. A trial is set for April.
Mitchell is accused in the federal case of operating an illegal gambling enterprise that took in millions of dollars. He is accused of both hosting illegal high-stakes poker games at his home and illegally taking bets on sporting events.
Mitchell has pleaded not guilty. His defense attorney has said he is a professional gambler who acted legally and paid taxes on his gambling income.
The FBI agent described Mitchell in the affidavit as a sports “bookie” who has been engaged in illegal gambling activity from at least 1990 until November 2010 when his wife was brutally beaten to death.
Before Wednesday, Ross had denied to the media any involvement with Mitchell. In a phone interview Friday, Ross told The Oklahoman he never bet on sporting events and never sent Mitchell any checks.