Anatoly Chubais, who quit his post as a Kremlin special envoy due to the war in Ukraine, has been hospitalised in Europe with a rare autoimmune disorder that attacks the nervous system, a Russian journalist quoted him as saying.

Chubais has been diagnosed with Guillain-Barre syndrome, a disease caused by the immune system damaging the peripheral nervous system, Russian reporter and political activist Ksenia Sobchak quoted him as saying on Telegram.

It was unclear exactly where in Europe the 67-year-old Chubais, who left Russia immediately after resigning in March, was hospitalised. Chubais could not be reached for immediate comment.

Chubais, who once served as former President Boris Yeltsin’s chief of staff, served as President Vladimir Putin’s special representative for ties with international organisations before his resignation.