law: 4. Oaths or affirmations to be made by witnesses, interpreter and jurors.-
  (1) Oaths or affirmations shall be made by the following persons, namely:-
  (a) all witnesses, that is to say, all persons who may lawfully be examined, or give, or be required to give, evidence by or before any court or person having by law or consent of parties authority to examine such persons or to receive evidence;
  (b) interpreters of questions put to, and evidence given by, witnesses; and
  (c) jurors: Provided that where the witness is a child under twelve years of age, and the court or person having authority to examine such witness is of opinion that, though the witness understands the duty of speaking the truth, he does not understand the nature of an oath or affirmation, the foregoing provisions of this section and the provisions of section 5 shall not apply to such witness; but in any such case the absence of an oath or affirmation shall not render inadmissible any evidence given by such witness nor affect the obligation of the witness to state the truth.
  (2) Nothing in this section shall render it lawful to administer, in a criminal proceeding, an oath or affirmation to the accused person, unless he is examined as a witness for the defence, or necessary to administer to the official interpreter of any court, after he has entered on the execution of the duties of his office, an oath or affirmation that he will faithfully discharge those duties.