The presiding officer may permit prepared testimony of a witness on direct examination, in either narrative or question and answer form, to be incorporated into the record in a contested case. The offering party must provide copies of such testimony to the agency and to all other parties of record at a time designated by the presiding officer. The witness must swear or affirm to the truth of the testimony in the same manner required for live testimony. Such witness shall be subject to cross-examination and the prepared testimony shall be subject to a motion to strike in whole or in part.