All penalties which shall accrue under title 28 of the Revised Statutes shall be sued for and recovered in an action in the nature of an action of debt, in the name of the United States, before any court having jurisdiction of the same, in any State or Territory in which the defendant shall be arrested or found, the one half to the use of the informer and the other half to the use of the United States, except when the prosecution shall be first instituted on behalf of the United States, in which case the whole shall be to their use.
(R.S. § 2124.)