A new trial against jailed Kremlin critic Alexei Navalny began Tuesday inside the penal colony outside Moscow where he is held, in a case that could see his jail time extended by more than a decade.

A video link showed Navalny in a prison uniform at the hearing, an AFP journalist reported. 

The opposition leader, who has spent a year behind bars after surviving a poison attack that he blames on the Kremlin, is accused of fresh fraud charges.

Navalny is currently serving a two-and-a-half year sentence, but the new charges could see his time behind bars significantly extended.

The hearing of Moscow's Lefortovsky district court is taking place inside the maximum security prison where he is being held in Pokrov, some 100 kilometres (60 miles) east of Moscow.

The video link showed his wife Yuliya Navalnaya inside the room where the trial is heard, a day after she had demanded access to the proceedings.  

Amnesty International described it as a "sham trial, attended by prison guards rather than the media."

The new fraud case against Navalny was launched in December 2020, while the 45-year-old was recovering in Germany after narrowly surviving a nerve agent poisoning.

Investigators accuse Navalny of stealing for personal use more than $4.7 million of donations that were given to his political organisations. The charges carry a maximum penalty of 10 years in prison.

The start of the trial comes as talks over Ukraine between Russia and the West intensify, with German Chancellor Olaf Scholz the latest Western leader due in Moscow for talks with Putin.