(1) Evidence that was obtained—
(a) improperly or in contravention of a law; or
(b) in consequence of an impropriety,
shall not be admitted in proceedings unless the probative value of the evidence outweighs the prejudicial effect of the evidence.
(2) Without limiting subsection (1), where—
(a) a confession was made during or in consequence of questioning; and
(b) the person conducting the questioning knew, or ought reasonably to have known that—
(i) the doing or omission of an act was likely to impair substantially the ability of the person being questioned to respond rationally to the questioning, or
(ii) the making of a false statement was likely to cause the person who was being questioned to make a confession,
but nevertheless, in the course of that questioning, the person conducting the questioning did or omitted to do the act or made the false statement, evidence of the confession, and evidence obtained in consequence of the confession, shall be taken to have been obtained improperly.
(3) For the purposes of subsection (1), the court shall take into account, inter alia, the following matters—
(a) the probative value of the evidence;
(b) the importance of the evidence in the proceedings;
(c) the nature of the relevant offence, cause of action or defence and the nature of the subject-matter of the proceedings;
(d) the gravity of the impropriety or contravention;
(e) whether the impropriety or contravention was deliberate or reckless;
(f) whether any other proceedings, whether or not in a court, has been or is likely to be taken into relation to the impropriety or contravention;
(g) the difficulty, if any, of obtaining the evidence without impropriety or contravention of law.