Any person claiming to be an owner or lien holder of the named property may appear at any time within thirty days after service on him of notice to appear or on or before the date certain set forth in any order of publication under § 8.01-317 or such longer time as the court in its discretion may allow to prevent a miscarriage of justice. Any person without actual or constructive notice of the forfeiture proceedings claiming to be an owner or lienholder may appear at any time before final judgment of the trial court and be made a party to the action. Such appearance shall be by answer, under oath, which shall clearly set forth (i) the nature of the defendant’s claim; (ii) the exact right, title or character of the ownership or interest in the property and the evidence thereof; and (iii) the reason, cause, exemption or defense he may have against the forfeiture of the property.