A secretive figure with extensive connections to the Russian mafia, he is considered one of the leading candidates to succeed Alexander Bortnikov as director of the FSB.
[4] Korolev's father was a Soviet military commander and a friend and hunting partner of Viktor Zubkov, former prime minister of Russia and now chairman of the board of Gazprom.
Beginning around 1993, Korolev worked in a private security company that guarded the Mebel-Market chain of furniture stores, where Serdyukov was deputy director.
[4] At the Ministry of Defense, Korolev oversaw the GRU, where some say he was largely left in charge of the military intelligence agency's day-to-day operations.
[9] In 2004, Saint Petersburg Police found that Korolev maintained a relationship with Oleg Makovoz, owner of a security firm involved in a series of high-profile contract killings, and a member of the "Brothers' Gang", a criminal enterprise based in Irkutsk sanctioned by the United States in 2017.
[9] As a result of the Makovoz case, Korolev was transferred to the Federal Taxation Service, led by Anatoly Serdyukov, before both moved to the Ministry of Defense in 2007.
[9] In 2007, then-adviser to Minister of Defense, Korolev was wiretapped by Spanish investigators talking to the leader of the Tambov Gang, Gennady Petrov.
[5] The Spanish criminal investigation also implicated Korolev in helping the Tambov Gang secure a promotion for Nikolai Aulov, then the head of the Main Directorate of the Ministry of Internal Affairs (MVD) in the Central Federal District.
[9] Following Serdyukov's departure Korolev moved to the FSB in September 2011, appointed head of the Internal Security Directorate (known as the 6th Service or CSS (Russian: «Шестерка»)).
This department also carried out operational support in the case of the former governor of the Sakhalin Oblast, Alexander Khoroshavin, and the mayor of Vladivostok, Igor Pushkarev.
Despite the sad ending of General Borys Kolesnikov, the generals of another department: Maksimenko and Nikandrov from the TFR, tried to resist the appointment of Sergei Korolev to the post of head of the SEB, one of the key units in the FSB, which, due to a combination of circumstances that led to a criminal investigation "Shootout on Rochdelskya Street [ru]" also ended tragically for them.
[3] According to Novaya Gazeta, Korolev is the godfather of FSB Lieutenant Colonel Marat Medoev, a famed sniper and plankowner of Russian SSO, rumored to be his personal deputy.