Masimov also served as director of Kazakhstan’s all-powerful National Security Committee (NSC). Founded in 1992, the NSC is one of several successor agencies to the Soviet-era Committee for State Security (KGB). The agency performs a wide array of counterintelligence functions, while also commanding a sizeable border guard force and having responsibility for counter-terrorism and covert action operations. It works closely with the Foreign Intelligence Service (also known as Syrbar, or KNB), which is Kazakhstan’s primary external intelligence agency.

In a surprise move, the government of Kazakh President Kassym-Jomart Tokayev, Nazarbayev’s hand-picked successor, fired Masimov from his NSC post on Wednesday. Masimov was reportedly replaced with his chief bodyguard. Less than 24 hours later, the NSC announced it had arrested Masimov, along with several other current and former government officials. In a statement posted on its website, the NSC said Masimov had been arrested as part of a “pre-trial investigation into high treason”. It is not currently known if this move is linked to the ongoing nationwide protests, which have resulted in the deaths of over 160 and the arrests of nearly 5,000 people.

In a report published on Friday, The New York Times, which was able to access the NSC statement about Masimov’s arrest, suggests that Masimov firmly belongs to the pro-Nazarbayev faction of the Kazakh government. This faction is now coming under increasing pressure by the pro-Tokayev faction, which wants to be seen as taking action against the corruption and nepotism associated with the Nazarbayev years. In doing so, President Tokayev is hoping to draw attention away from the shortcomings of his own rule, according to The Times.