The jury trial for Teddy Mitchell and nine other defendants has been postponed to April 9.
Mitchell, his two sons, six other men and a Costa Rican company are accused in an 81-count indictment of involvement in an illegal gambling operation. A federal grand jury indicted them Sept. 19.
The trial was set to begin Nov. 13 in federal court in Oklahoma City.
Prosecutors allege Mitchell, 58, made millions of dollars hosting illegal high-stakes poker games at his Oklahoma City home and illegally taking bets on sporting events. He has pleaded not guilty.
U.S. District Judge David Russell on Friday delayed the trial so defense attorneys can have adequate time to prepare. The judge agreed the case is complex.
Mitchell's attorneys first sought the delay.
Mitchell's attorneys reported prosecutors so far have turned over to them 2,400 pages of reports and records and 38 CDs/DVDs of video evidence and recorded calls.
Prosecutors are expected to turn over thousands of more records to defense attorneys later.
Oklahoma City police detectives, meanwhile, are continuing to investigate the 2010 beating death of Mitchell's wife.
Julie Mitchell, 34, was killed inside the couple's home while Teddy Mitchell was traveling to California.