Those indicted are the IBF president Robert W Lee Snr and his son, Robert Lee Jnr, both of New Jersey, Donald William Brennan, of Virginia, a former boxing commissioner and past president of the US Boxing Association, which later became the IBF, and the Colombian Francisco Fernandez.
The 32-count indictment - details of which will be released later - includes charges of conspiracy and racketeering. During its two-year investigation, the grand jury subpoenaed all IBF records since 1982 on rankings and contracts for fights, as well as checks, invoices, expense forms and telephone records, the IBF lawyer, Walter Stone, revealed.
The investigation preceded the controversial Evander Holyfield-Lennox Lewis heavyweight title draw, which prompted New York law enforcement agencies to start their own investigation of the IBF.
The grand jury heard in April from the judge criticised for her scoring in that fight. Eugenia Williams, of Atlantic City, told the grand jury that no one attempted to sway her decision. A rematch is scheduled for next Saturday in Las Vegas - with Williams again the IBF-chosen judge.
The IBF and two other sanctioning groups - the World Boxing Association and the World Boxing Council - by their rules and rankings, play a large role in determining whom a boxer fights. Boxers who defy the groups may risk losing the chance to be declared a champion.