Relevancy of statements: signed answers to summons may be admitted when maker is unavailable or court permits in interest of justice. Section 136 renders signed statements made on appearance under a summons issued under section 70 relevant in prosecutions under the Act for proving the truth of their contents, but only where the maker is unavailable to give evidence (dead, cannot be found, incapable, kept away, or presence would cause unreasonable delay or expense) or where the maker is examined as a witness and the court, considering the circumstances, admits the statement in the interest of justice.