P is engaged in the door-to-door and mail-order sale of encyclopedias and related reference publications. D charged P with unfair methods of competition and unfair or deceptive acts or practices in connection with its sales activities, pricing representations, promotion techniques, recruitment practices, debt collection, and mail order operations. The case was assigned to an Administrative Law Judge (ALJ), who during the hearings retired before rendering a decision. A second ALJ recused himself. Brand, the third ALJ assigned to the case, began hearings and decided to recall many of the witnesses who had previously testified. Four months before completion of the hearings, Brand informed the parties that he had served as an attorney-advisor to former Commissioner MacIntyre during which period Grolier was intermittently investigated and charged by D. Commissioner MacIntyre attended at least one meeting between P and representatives of D. P requested that Brand disqualify himself. Brand denied the request, claiming that he did not recall working on matters involving P while serving as legal advisor to the Commissioner. P filed a formal motion for disqualification and removal of Brand, and seeking discovery of records which would have tended to show the nature and extent of Brand's contact with P's case. D denied both the motion for disqualification and the requested discovery. Brand issued his decision and recommended a cease and desist order. D adopted in large part the decision and order and reaffirmed denial of the disqualification motion and request for discovery. P appealed. P claims D violated both section 554(d) and the Due Process guarantee of the Fifth Amendment.