Katrien de Cuyper was a Belgian girl whose 1991 disappearance was linked to the [[Marc Dutroux]] network through testimony in the [[X-Dossier]]. X1 ([[Regina Louf]]) described witnessing de Cuyper's murder at a castle, providing details that matched aspects of the case. Members of the [[Morkhoven Workgroup]] believed they had identified de Cuyper in pornographic photos found on the [[Apollo Disks]] seized from [[Gerrit-Jan Ulrich]]'s apartment in Zandvoort.[^1] ### Footnotes [^1]: Dovey, S. (2023). *Eye of the Chickenhawk*. United States: Thehotstar.