39 CFR 959.17 - Evidence.
(a) Except as otherwise provided in these rules, the rules of evidence governing civil proceedings in matters not involving trial by jury in the District courts of the United States shall govern. However, such rules may be relaxed to the extent that the presiding officer deems proper to insure a fair hearing. The presiding officer shall exclude irrelevant, immaterial or repetitious evidence.
(b) Testimony shall be under oath or affirmation and witnesses shall be subject to cross-examination.
(c) Agreed statements of fact may be received into evidence.
(d) Official notice or knowledge may be taken of the types of matters of which judicial notice or knowledge may be taken.
(e) The written statement of a competent witness may be received into evidence provided that such statement is relevant to the issues, that the witness shall testify under oath at the hearing that the statement is in all respects true, and, in the case of expert witnesses, that the statement correctly states his or her opinion or knowledge concerning the matters in question.
(f) A party who objects to the admission of evidence shall make a brief statement of the grounds for the objection. Formal exceptions to the rulings of the presiding officer are unnecessary.