Alexei Navalny, the jailed Russian opposition leader, has died at 47, the prison service of the Yamalo-Nenets region said today.

Navalny had been a fierce critic of president Vladimir Putin, and was jailed in 2021 following a string of convictions widely considered to have been politically motivated.

He had previously led the opposition party Russia in the Future, and founded the Anti-Corruption Foundation in protest against corruption in Putin's government.

Kremlin spokesperson Dmitry Peskov said Russia's penitentiary service was “making all checks” regarding Navalny's death, but that he had no information about the matter.

Vladimir Putin has been informed of his death, Russian state-run media site TASS reported.

The full statement from the Office of the Federal Penitentiary Service of Russia read: “On February 16, 2024, in correctional colony No 3, convict A A Navalny felt unwell after a walk, almost immediately losing consciousness.”

“The institution's medical workers immediately arrived, and an emergency medical team was called.

“All necessary resuscitation measures were carried out, but they did not yield positive results.

“Emergency medical doctors confirmed the death of the convict.”