—(1) A statement shall not be admissible in evidence in any criminal proceedings by virtue of section 270(1)(a) or (b)(ii), (iii) or (iv), if it was made after the commencement of investigations into the offence which is the subject-matter of the proceedings.
(2) Subject to subsection (1), evidence under section 270(1)(b) may not be given on behalf of a party to the proceedings, unless —
that party has previously served a notice in writing on each of the other parties of his intention to introduce the evidence;
the notice complies with the requirements of subsection (3); and
the leave of the court is obtained.
(3) The requirements referred to in subsection (2)(b) are as follows:
the notice must state on which of the grounds in section 270(1)(b) it is claimed that the statement is admissible;
in the case of a statement not made in a document, the notice must state the manner in which it was made (whether orally or otherwise), and must also state —
the time and place at which the statement was made;
the name of the maker of the statement and (unless he is dead) his address, if known;
the name and address of the person who heard or otherwise perceived the statement being made; and
the substance of the statement or, if it was made orally and the actual words used in making it are material, the words used; and
in the case of a statement made in a document, the notice must contain or have attached to it a copy of that document, or of the relevant part of it, and must also state —
if the maker of the document is different from the maker of the statement, the name of the maker of the document and (unless he is dead) his address, if known,
if the information is not readily apparent from the document or the relevant part of the document.