3. (a) The investigative authority shall have the power and obligation to obtain all the information necessary to the inquiry.2581 The persons conducting the investigation shall have at their disposal all the necessary budgetary and technical resources for effective investigation. They shall also have the authority to oblige all those acting in an official capacity allegedly involved in torture or ill-treatment to appear and testify. The same shall apply to any witness. To this end, the investigative authority shall be entitled to issue summonses to witnesses, including any officials allegedly involved, and to demand the production of evidence. (b) Alleged victims of torture or ill-treatment, witnesses, those conducting the investigation and their families shall be protected from violence, threats of violence or any other form of intimidation that may arise pursuant to the investigation. Those potentially implicated in torture or ill-treatment shall be removed from any position of control or power, whether direct or indirect, over complainants, witnesses and their families, as well as those conducting the investigation. 4. Alleged victims of torture or ill-treatment and their legal representatives shall be informed of, and have access to, any hearing, as well as to all information relevant to the investigation, and shall be entitled to present other evidence. 5. (a) In cases in which the established investigative procedures are inadequate because of insufficient expertise or suspected bias, or because of the apparent existence of a pattern of abuse or for other substantial reasons, States shall ensure that investigations are undertaken through an independent commission of inquiry or similar procedure. Members of such a commission shall be chosen for their recognized impartiality, competence and independence as individuals. In particular, they shall be independent of any suspected perpetrators and the institutions or agencies they may serve. The commission shall have the authority to obtain all information necessary to the inquiry and shall conduct the inquiry as provided for under these Principles. (b) A written report, made within a reasonable time, shall include the scope of the inquiry, procedures and methods used to evaluate evidence as well as conclusions and recommendations based on findings of fact and on applicable law. Upon completion, the report shall be made public. It shall also describe in detail specific events that were found to have occurred and 258. Under certain circumstances, professional ethics may require information to be kept confidential. These requirements should be respected. Appendices ► Page 105