Defense attorneys for reputed mobster James "Whitey" Bulger have asked a judge to delay opening statements in his racketeering trial.

In a motion filed Monday June 10th, Bulger's lawyers asked for a stay of proceedings while they conduct their own investigation into a man expected to be a key witness against Bulger.

The defense says John Martorano, who admitted to killing 20 people, has committed crimes since his release from federal prison and has been shielded from investigation by law enforcement.

Prosecutors have denied the allegations.

Defense lawyers are asking for documents in the case and the prosecution's refusal to turn them over is "inexcusable, inexplicable and unconstitutional."

The judge has said she wants opening statements on Wednesday, following jury selection, which is expected to continue today.