22 C.F.R. § 92.57
When a witness is examined on the basis of oral interrogatories, the counsel for the party requesting the deposition has the right to conduct a direct examination of the witness without interruption except in the form of objection by opposing counsel. The opposing counsel has the same right on cross-examination. Cross-examination may be followed by redirect and recross-examinations until the interrogation is complete. The notarizing officer taking the deposition should endeavor to restrain counsel from indulging in lengthy colloquies, digressions, or asides, and from attempts to intimidate or mislead the witness. The notarizing officer has no authority to sustain or overrule objections but should have them recorded as provided in § 92.59 . Instead of taking part in the oral examination of a witness, the parties notified of the taking of a deposition may transmit written interrogatories to the notarizing officer. The notarizing officer should then question the witness on the basis of the written interrogatories and should record the answers verbatim. (Rules 30 (c) and 31 (b), Rules of Civil Procedure for the District Courts of the United States.)
22 C.F.R. §92.57