(a) Where debts are due from a defaulting or delinquent postmaster, contractor, or other officer, agent or employee of the Post Office Department, a warrant of attachment may issue against all property and legal and equitable rights belonging to him, and his sureties, or either of them, where he—

(1) is a nonresident of the district where he was appointed, or has departed from that district for the purpose of permanently residing outside thereof, or of avoiding the service of civil process; and

(2) has conveyed away, or is about to convey away any of his property, or has removed or is about to remove the same from the district wherein it is situated, with intent to defraud the United States.

(b) When the property has been removed, the marshal of the district into which it has been removed, upon receipt of certified copies of the warrant, may seize the property and convey it to a convenient place within the jurisdiction of the court which issued the warrant. Alias warrants may be issued upon due application. The warrant first issued remains valid until the return day thereof.