3(1)Subject to sub-paragraph (2) below, a person authorised by or on behalf of the Secretary of State may for the purpose—
(a)of securing compliance with orders made and directions given by the Secretary of State under this Act;
(b)of checking estimates and forecasts or verifying returns and information provided in response to directions under paragraph 1 of this Schedule ;
at all reasonable hours and on production (if so required) of his authorisation, go on any premises and there make such enquiries and inspections, and purchase or take such samples of any substance, as are allowed by the terms of his authorisation or he thinks necessary for those purposes.
(2)The powers of this paragraph are not exercisable—
(a)for the purpose only of securing compliance with orders under section 15 of this Act;
(b)except when an Order in Council under section 3 of this Act is in force, for the purpose only of securing compliance with orders under section 1(1).
(3)The reference in this paragraph to premises includes vehicles and vessels, but not any premises used only as a dwelling.