The NFL sent a letter to Jerry Jones' attorney accusing the Dallas Cowboys owner of "conduct detrimental to the league's best interests" over his objection to a contract extension for Roger Goodell.

Jones hired attorney David Boies and threatened to sue the NFL if Goodell's contract extension was approved by the compensation committee. All 32 owners voted unanimously in May to let the committee finalize a deal with Goodell.

Jones has denied that his objections to the extension are tied to Goodell's decision to suspend Cowboys star Ezekiel Elliott for six games over alleged domestic violence.