1If a witness refers to facts he has been told of by other persons, the court, upon request of a party or ex officio, shall order to summon these persons to testify.
2Failure to comply with the provisions of paragraph 1, results in the non-usability of the statements related to the facts of which the witness has been informed by other persons, unless the questioning of these persons is impossible because they are dead, seriously ill or untraceable.
3A witness shall not be questioned on facts heard from the persons who are obliged to keep their professional or state secret, unless the aforementioned persons have made statements on the same facts or have disclosed them in some other way.
4The testimony of persons who refuse or are not able to indicate the person or source that informed them of the facts under questioning shall not be used.
EN