28 U.S.C. § 2717: Discharge

The court, or a judge thereof, upon—(1) application of the party when property has been attached and (2) execution to the United States of a penal bond, approved by a judge, in double the value of the property attached and conditioned upon the return of the property or the payment of any judgment rendered by the court may discharge the warrant of attachment as to the property of the applicant.