A federal judge has tossed a stock-option backdating case against Broadcom Corp. co-founder Henry T. Nicholas III and former Chief Financial Officer William Ruehle because of prosecutorial misconduct.

U.S. District Judge Cormac J. Carney also Tuesday asked the government to show cause why a separate drug indictment against Nicholas should not also be thrown out.

The stunning move comes after Carney also vacated a guilty plea by Broadcom co-founder Henry Sameuli in the same case.

Carney found that prosecutors had tried to prevent three key defense witnesses from testifying, had improperly contacted attorneys for defense witnesses and had leaked information about grand jury proceedings to the press.