A hearsay statement is not admissible to prove the fact that an earlier hearsay statement was made unless—
either of the statements is admissible under section 117, 119 or 120,
all parties to the proceedings so agree, or
the court is satisfied that the value of the evidence in question, taking into account how reliable the statements appear to be, is so high that the interests of justice require the later statement to be admissible for that purpose.
In this section "hearsay statement" means a statement, not made in oral evidence, that is relied on as evidence of a matter stated in it.