Related Rule
Practice Relating to Rule 98. Enforced Disappearance
Under the International Crimes Act (2003) of the Netherlands, “enforced disappearance of persons” is a crime against humanity, when committed as part of a widespread or systematic attack directed against any civilian population, with knowledge of the attack. 
Netherlands, International Crimes Act, 2003, Article 4(1)(i).
Enforced disappearance is defined as:
the arrest, detention or abduction of persons by, or with the authorization, support or acquiescence of a State or a political organization, followed by a refusal to acknowledge that deprivation of freedom or to give information on the fate or whereabouts of those persons, with the intention of removing them from the protection of the law for a prolonged period of time. 
Netherlands, International Crimes Act, 2003, Article 4(2)(d).