MELEKHOVO: A Russian court convicted imprisoned opposition leader Alexei Navalny of extremism changes and sentenced him to 19 years in prison on Friday.

Navalny is already serving a nine-year term on a variety of charges that he says were politically motivated.

The new charges against the politician relate to the activities of Navalny's anti-corruption foundation and statements by his top associates.

In 2021, Russian authorities outlawed the foundation and the vast network of Navalny's offices in Russian regions, calling them extremist organisations and exposing anyone involved to possible prosecution. Navalny's allies say the charges retroactively criminalise all the foundation's activities since its creation in 2011.

Navalny, 47, is President Vladimir Putin's fiercest foe and has exposed official corruption and organised major anti-Kremlin protests. He was arrested in January 2021 upon returning to Moscow after recuperating in Germany from nerve agent poisoning. He blamed that poisoning on the Kremlin, which denied involvement.

The authorities previously sentenced him to 2 1/2 years in prison for parole violations and then to another nine years on charges of fraud and contempt of court. It wasn't immediately clear if he will serve the new sentence concurrently with those.