21.—(1) The enforcement authority may by notice require a person on whom a variable monetary penalty is imposed to pay the costs incurred by the enforcement authority in relation to the imposition of the penalty up to the time of its imposition.
(2) The notice must specify the amount required to be paid.
(3) The person on whom the notice is served may require the enforcement authority to provide a detailed breakdown of the amount specified in the notice.
(4) The person required to pay costs is not liable to pay any costs shown by the person to have been unnecessarily incurred.
(5) In this Article, “costs” include in particular—
(a)investigation costs;
(b)administration costs; and
(c)costs of obtaining expert advice (including legal advice).