Russia · founded 1995 · Russia's main domestic security service.
Episode: CLASSIFIED — COMING SOON
Section: Russia and the USSR
Case files (2): Litvinenko Inquiry: polonium poisoning in London · Navalny poisoning: the alleged FSB unit
Leaks (2): Operation Triangulation and the FSB's claim · The Vulkan Files
The UK public inquiry found the poisoning was probably carried out by two men acting probably under FSB direction, and approved by the FSB chief and President Putin; these are 'probably' findings.
BBC News: President Putin 'probably' approved Litvinenko murder ↗
The OPCW's summary confirms a cholinesterase-inhibitor with structural similarities to scheduled toxic chemicals; the link to an FSB unit rests on Bellingcat's open-source reporting, and this page makes no finding.