Slovak police , Interpol , and Belgian police have been following leads on Dutroux 's activities in Slovakia and the neighbouring Czech Republic where he is known to have made frequent visits .
<response> <misc>Slovak</misc> police , <organization>Interpol</organization> , and <misc>Belgian</misc> police have been following leads on <person>Dutroux</person> 's activities in <location>Slovakia</location> and the neighbouring <location>Czech Republic</location> where he is known to have made frequent visits . </response>