The West Virginia Supreme Court said Tuesday that a man could withdraw a guilty plea he made in 2002 for a robbery and rape because prosecutors had withheld DNA testing results suggesting that he was probably innocent.

The case will reverberate more widely, legal experts said, because the West Virginia justices have provided the clearest decision yet on what has been an ambiguous, but important, question about the constitutional rights of criminal defendants.

According to the firmly established Brady rule — enunciated in the 1963 Supreme Court case Brady v. Maryland — prosecutors must turn over potentially exculpatory information to defendants at criminal trials.

But whether they must also do so during the process of plea bargaining, before a defendant formally admits guilt and is sentenced, has been disputed. Several state and federal courts have suggested that the same principle should apply to such proceedings, some have disagreed, and the Supreme Court has not given a definitive answer.