Witnesses are obligated to provide true and complete testimony. If testimony is refused without a valid reason, both coercive measures and disciplinary penalties can be imposed, or the person concerned may be obliged to compensate for the costs incurred. Additionally, false testimony before an administrative authority is criminally punishable under § 289 of the Penal Code (StGB).
Only in legally specified exceptional cases is the witness entitled to refuse testimony. The most important of these are:
- Questions whose answers would result in immediate financial loss to the witness or one of their relatives or the risk of criminal prosecution
- Questions that the witness could not answer without violating a duty of confidentiality (e.g., doctors)
- Questions concerning circumstances that were entrusted to a person authorized for professional representation (e.g., notaries, lawyers) by the party in that capacity
