(2) Without prejudice to the generality of subsection (1), it shall, subject to section 19 , be a defence to a defamation action for the defendant to prove that—
(a) the statement was published to a person or persons who—
(i) had a duty to receive, or interest in receiving, the information contained in the statement, or
(ii) the defendant believed upon reasonable grounds that the said person or persons had such a duty or interest, and
(b) the defendant had a corresponding duty to communicate, or interest in communicating, the information to such person or persons.