Well-known post-Soviet reformer Anatoly Chubais, who left Russia following the Kremlin invasion of Ukraine, is reported to be in intensive care in a European hospital.
Russian TV personality Ksenia Sobchak, a friend of Chubais, wrote on Telegram on July 31 that she had spoken with Chubais's wife, Avdotya, and that he was suffering from Guillain-Barre syndrome. She did not say where he was being treated.
Guillain-Barre is a rare disorder in which the body’s immune system attacks the nerves.
Sobchak quoted Chubais as saying his condition was “moderate, stable.”
Chubais's state of health or whereabouts could not immediately be confirmed by news agencies.
Before leaving Russia in March, Chubais resigned his position as Russian President Vladimir Putin's envoy for stable development, without giving a reason for doing so.
Many observers speculated that it could signal the highest-profile protest inside the Kremlin against Moscow's unprovoked invasion of Ukraine.
Bloomberg reported that Chubais had expressed opposition to the invasion of Ukraine upon his departure.
Chubais, 67, is well-known in Russia, having held high-profile posts since the early 1990s, when he oversaw privatization efforts under President Boris Yeltsin.
Kira Yarmysh, the press secretary of jailed anti-corruption campaigner Aleksei Navalny, wrote on Twitter that “This is the Kremlin's reputation: no one really doubts that Chubais was poisoned.”
Several opponents of Putin’s rule have suffered from poisoning attacks, often outside of Russia.
The Kremlin has denied involvement despite strong evidence in many cases implicating Russian authorities.