The head of Russia's military intelligence agency, the GRU, has died from illness, according to officials in Moscow.
He reportedly fell ill after President Vladimir Putin berated him for botching an assassination in the UK and failing to hack into the global chemical weapons headquarters earlier this year.
Igor Korobov died from a "serious illness" on Wednesday, Russia's defense ministry told the state-run TASS news agency on Thursday.
The 62-year-old joined the GRU in 1985 and served in various positions including overseeing foreign agents. He became its head in 2016. He was named a Hero of Russia, the state's highest award, for his service.
The specifics of Korobov's illness are not clear, but it allegedly came after Putin reprimanded him for a series of embarrassing blunders by Russia's spies abroad earlier this year.
According to Russia's MBK news site, Putin summoned Korobov to his office in mid-September to scold him, and Korobov fell ill upon returning to his home in an elite residential complex in Moscow. MBK was founded by Mikhail Khodorkovsky, a prominent Kremlin critic.
Russia's military leaders reportedly called the GRU "deeply incompetent," "infinitely careless," and "morons" after Western investigators accused its agents of being behind the nerve agent poisoning of former Russian spy Sergei Skripal in Salisbury, England.
Agents were also accused of being behind an attempted hack into the Organisation for the Prohibition of Chemical Weapons.
Both missions ultimately failed. Skripal and his daughter Yulia, who was also poisoned, survived the attempted assassination. One British woman who unwittingly handled the substance on a separate occasion died.
Britain in September accused two Russian men of being behind the poisoning, and Prime Minister Theresa May said that they were officers of the GRU.
The suspects gave an interview to Russian state TV claiming to be tourists, but t he investigative website Bellingcat named the two men as Colonel Anatoliy Chepiga and Dr Alexander Yevgenyevich Mishkin.
The alleged GRU agents who attempted to hack into the Organisation for the Prohibition of Chemical Weapons were also caught red-handed, and ultimately sent back to Russia.
Putin will now have to appoint Korobov's successor as tension continues to rise between him and Western countries, notably the US and UK.
Korobov's predecessors, Igor Sergun, also died unexpectedly in 2016. The Russian government said he suffered a heart attack in Moscow, but investigators at Stratfor said he died on a different day in Lebanon.