(1) Where the Commissioners investigate or propose to investigate any matter with a view to determining -

(a) whether there are grounds for believing that a relevant offence has been committed, or

(b) whether a person should be prosecuted for such an offence,

the matter is to be treated as an assigned matter.

(2) In paragraph (1) "assigned matter" has the meaning given by section 1(1) of CEMA [The definition of "assigned matter" in section 1(1) of CEMA was amended by the Commissioners for Revenue and Customs Act 2005 (c. 11), Schedule 4, paragraph 22(a); the Scotland Act 2012 (c. 11), section 24(7); and the Wales Act 2014 (c. 29), section 7(1).].

(3) In this regulation a "relevant offence" means an offence under Part 4 (trade).

(3A) The Commissioners may not investigate the suspected commission of a relevant offence listed in paragraph (3B) or (3C), unless the suspected offence has been the subject of -

(a) a referral to the Commissioners by the Secretary of State, or

(b) a decision by the Commissioners to treat the suspected offence as if it had been referred to them under sub-paragraph (a).