The British government claims that 'Novichok' poisons, developed 30 years ago in the Soviet Union, affected a British double agent. But such substances may not exist at all. The British government further says that the Russian government is responsible for the incident and has announced penalties against the country.
A comparable incidents happened in 2001 in the United States. Envelopes with Anthrax spores were sent to various politicians. Some people died. The White House told the FBI to blame al-Qaeda but the Anthrax turned out to be from a U.S. chemical-biological weapon laboratory. The case is still unsolved.