A year ago, a federal judge in St. Louis issued a then-sealed order in which he found that E.I. du Pont de Nemours and Co. “knowingly committed a fraud upon the court” in a high-profile patent dispute with Monsanto Co. On Friday, it was learned that the judge had recently unsealed his order, adding to the woes of DuPont, which had already been hit with a $1 billion verdict in the case in August.

The suit has pitted Winston & Strawn, for Monsanto, against Kirkland & Ellis and Boies Schiller & Flexner, for DuPont.