(a)
Establishment of central file
There shall be established in the office of the Commissioner, for the use of security and enforcement agencies of the Government of the United States, a central index, which shall contain the names of all aliens heretofore admitted or denied admission to the United States, insofar as such information is available from the existing records of the Service, and the names of all aliens hereafter admitted or denied admission to the United States, the names of their sponsors of record, if any, and such other relevant information as the Attorney General shall require as an aid to the proper enforcement of this chapter.
(d)
Certification of search of Service records
A written certification signed by the Attorney General or by any officer of the Service designated by the Attorney General to make such certification, that after diligent search no record or entry of a specified nature is found to exist in the records of the Service, shall be admissible as evidence in any proceeding as evidence that the records of the Service contain no such record or entry, and shall have the same effect as the testimony of a witness given in open court.