(1) At any time after a referral under section 15M(2), an adjudication officer may, whether on application by the competent authority, by an undertaking or association of undertakings concerned in the matter which is the subject of the referral or of the adjudication officer's own motion, and where the adjudication officer is satisfied that such direction is necessary to the determination of the issues before the adjudication officer -

(a) direct authorised officers of the competent authority, or the undertaking or association of undertakings concerned, (each of which, in this section, is referred to as a 'party') to answer (whether on oath or otherwise) an identified question in whatever manner or form the adjudication officer may specify,

(b) direct a party to adduce evidence or produce books, documents and records in its power or control, and

(c) direct a party to clarify any issue of fact that an adjudication officer may deem necessary.