Power to examine witnesses
22.—(1)  In conducting an investigation under this Part, a police officer may examine orally any person who appears to be acquainted with any of the facts and circumstances of the case —
(a)whether before or after that person or anyone else is charged with an offence in connection with the case; and
(b)whether or not that person is to be called as a witness in any inquiry, trial, or other proceeding under this Code in connection with the case.
(2)  The person examined shall be bound to state truly what he knows of the facts and circumstances of the case, except that he need not say anything that might expose him to a criminal charge, penalty or forfeiture.
(3)  A statement made by any person examined under this section must —
(a)be in writing;
(b)be read over to him;
(c)if he does not understand English, be interpreted for him in a language that he understands; and
(d)be signed by him.