Moscow has opened a new criminal case against Russia’s top opposition politician Alexei Navalny, who is already serving a nine-year prison sentence, his spokeswoman said on Tuesday.

“A new criminal case was opened against Alexei Navalny while he’s in prison as a result of a ‘provocation’,” Kira Yarmysh said in English on Twitter.

Yarmysh said it was the tenth case against the Kremlin critic, who was already facing up to 35 years in prison.

His supporters see the charges as a punishment for challenging President Vladimir Putin.

In the latest case, Navalny is accused of “disorganisation of the activity of penitentiary institutions” which could see him face five more years in prison.

Yarmysh said the administration staged a “provocation” against Navalny by placing an inmate “with personal hygiene problems” in his cell.

The smell was so bad, Navalny “refused to go in there”, Yarmysh added.

According to informal prison “rules”, Yarmysh said that Navalny was expected to use force to kick the inmate out of his cell.

“He told the guards that he would not do it because this convict was not to blame and the administration was using him as a tool.”

After being “hit and dragged into the cell,” Navalny “grabbed (the inmate) by the scruff of the neck and dragged him to the door”, Yarmysh said.

The guards then “surrounded Navalny, pinned him to the wall, and the (penal) colony administration reported that a new criminal case was opened”.

Navalny was poisoned with Novichok, a Soviet-made nerve agent, on a trip to Siberia in 2020.

He underwent treatment in Germany and returned to Russia in January 2021, where he was arrested on landing at a Moscow airport. (AFP)