18.— (1) As soon as practicable after a direction is given or order is made under section 17, the member of the Garda Síochána who gave the direction or applied for the order shall ensure that any person who the member is aware is affected by the direction or order is given notice, in writing, of the direction or order unless—

(a) it is not reasonably practicable to ascertain the whereabouts of the person, or

(b) there are reasonable grounds for believing that disclosure to the person would prejudice the investigation in respect of which the direction or order is given.

(2) Notwithstanding subsection (1)(b), a member of the Garda Síochána shall give notice, in writing, of a direction or order under this section to any person who is, or appears to be, affected by it as soon as practicable after the Garda Síochána becomes aware that the person is aware that the direction has been given or order has been made.

(3) Nothing in subsection (1) or (2) requires notice to be given to a person to whom a direction is given or order is addressed under this section.

(4) A notice given under this section shall include the reasons for the direction or order concerned and advise the person to whom the notice is given of the person’s right to make an application under section 19 or 20 .

(5) The reasons given in the notice need not include details the disclosure of which there are reasonable grounds for believing would prejudice the investigation in respect of which the direction is given or order is made.