In the case of Harris v. Nelson, 1968, the U.S. Supreme Court ruled that federal courts do not have inherent authority to issue discovery orders in habeas corpus proceedings. The petitioner was a prisoner who sought a writ of habeas corpus and requested an order for discovery from the respondent warden to support his claim that he had been denied effective assistance of counsel during his trial. The District Court issued such an order but it was challenged by the respondent on appeal. In its decision, the Supreme Court held that there is no general right to discovery in habeas cases under existing law or rules at this time and any changes would need to be made through legislative action rather than judicial interpretation.

In the dissenting opinion for Harris v. Nelson, Justice William O. Douglas argued that federal courts should have the power to issue writs of discovery in habeas corpus proceedings when state remedies are inadequate or ineffective. He contended that denying this authority would undermine the constitutional right to a fair trial by preventing prisoners from obtaining necessary evidence to challenge their convictions effectively. Furthermore, he believed it was inappropriate for federal courts to rely on state court findings if those findings were based on incomplete or inaccurate information due to limitations in state discovery procedures. Therefore, he disagreed with the majority's decision and advocated for broader powers of discovery in federal habeas corpus cases.