; and (v) if the transcript is not signed by the witness during the 30-day period following the date on which the witness is first afforded a reasonable opportunity to examine the transcript, the Agency investigator shall sign the transcript and state on the record the fact of the waiver, illness, absence of the witness, or the refusal to sign, together with any reasons given for the failure to sign. (F) Certification by investigator The Agency investigator shall certify on the transcript that the witness was duly sworn by such Agency investigator and that the transcript is a true record of the testimony given by the witness, and the Agency investigator shall promptly deliver the transcript or send it by registered or certified mail to the custodian. (G) Copy of transcript The Agency investigator shall furnish a copy of the transcript (upon payment of reasonable charges for the transcript) to the witness only, except that the Agency may for good cause limit such witness to inspection of the official transcript of the testimony of such witness. (H) Witness fees Any witness appearing for the taking of oral testimony pursuant to a civil investigative demand shall be entitled to the same fees and mileage which are paid to witnesses in the district courts of the United States. (d) Confidential treatment of demand material (1) In general Documentary materials and tangible things received as a result of a civil investigative demand shall be subject to requirements and procedures regarding confidentiality, in accordance with rules established by the Agency. (2) Disclosure to congress No rule established by the Agency regarding the confidentiality of materials submitted to, or otherwise obtained by, the Agency shall be intended to prevent disclosure to either House of Congress or to an appropriate committee of the Congress, except that the Agency is permitted to adopt rules allowing prior notice to any party that owns or otherwise provided the material to the Agency and had designated such material as confidential. (e)