at all times be assisted by counsel. b) Any public officer or employee, or anyone acting under his order or in his place, who arrests, detains or investigates any person for the commission of an offense shall inform the latter, in a language known to and understood by him, of his rights to remain silent and to have competent and independent counsel, preferably of his own choice, who shall at all times be allowed to confer privately with the person arrested, detained or under custodial investigation. If such person cannot afford the services of his own counsel, he must be provided with a competent and independent counsel by the investigating officer. c) The custodial investigation report shall be reduced to writing by the investigating officer, provided that before such report is signed, or thumbmarked if the person arrested or detained does not know how to read and write, it shall be read and adequately explained to him by his counsel or by the assisting counsel provided by the investigating officer in the language or dialect known to such arrested or detained person, otherwise, such investigation report shall be null and void and of no effect whatsoever. d) Any extrajudicial confession made by a person arrested, detained or under custodial investigation shall be in writing and signed by such person in the presence of his counsel or in the latter's absence, upon a valid waiver, and in the presence of any of the parents, elder brothers and sisters, his spouse, the municipal mayor, the municipal judge, district school supervisor, or priest or minister of the gospel as chosen by him; otherwise, such extrajudicial confession shall be inadmissible as evidence in any proceeding. e) Any waiver by a person arrested or detained under the provisions of Article 125 of the Revised Penal Code, or under custodial investigation, shall be in writing and signed by such person in the presence of his counsel; otherwise such waiver shall be null and void and of no effect. f) Any person arrested or detained or under custodial investigation shall be allowed visits by or conferences with any member of his immediate family, or any medical doctor of priest or religious minister chosen by him or by any memberof his immediate family or by his counsel, or by any national non-government organization duly accredited by the Commission on Human Rights or by any international non-governmental organization duly accredited by the Office of the President. The person's "immediate family" shall include his or her spouse, fiance or fiancee, parent or child, brother or sister, grandparent or grandchild, uncle or aunt, nephew or neice, and guardian or ward. As used in this Act, "custodial investigation" shall include the practice of issuing an "invitation" to a person who is investigated in connection with an offense he is suspected to have