And also Prochukhan's and Pestyuk's partner-in-crime Konstantin Mamchur was clearly mentioned in this large Belgian investigation:

https://financelab.blog/2018/04/23/vermeend-ponzinetwerk-questra-kondigt-doorstart-in-belgie-aan/

https://s25.postimg.cc/hg6117gn3/prochukhan_belg.jpg