Article 589. § 1. A witness or expert who is not a Polish citizen and who, when summoned from abroad, appears voluntarily before the court, cannot be prosecuted or arrested, or put under preliminary detention either by reason of an offence relevant to the criminal proceedings, or of any other offence committed before he crossed the Polish border. The penalty imposed for such offence may not be executed with respect to him.
2. La Corte podrá dar seguridades a los testigos o expertos que comparezcan ante ella de que no serán enjuiciados o detenidos ni se restringirá su libertad personal por un acto u omisión anterior a su salida del Estado requerido.