PARIS, France–Oleg Orlov, a top Russian human rights campaigner who denounced Russia's offensive in Ukraine, is the latest critic of President Vladimir Putin to be put behind bars.

Days after opposition politician Alexei Navalny died in an Arctic prison, Orlov was on Tuesday sentenced to two-and-a-half years in prison.

Other opponents have been killed, narrowly escaped death or gone into exile.

Here are the best-known:

- Dead in prison -

Russia's most prominent opposition leader, Alexei Navalny, died on February 16 in a remote Arctic prison colony. He was serving a 19-year sentence.

The 47-year-old had been jailed in early 2021 after returning from Germany, where he was recovering from a near-fatal poisoning attack with Novichok, a Soviet-era nerve agent.

Navalny's supporters and family have accused Putin of killing him.

- Killed -

In February 2015, Boris Nemtsov, a Kremlin critic and a former deputy prime minister, was shot dead as he walked home across a Moscow bridge near the Kremlin.

Five Chechen men were convicted of killing Nemtsov but the mastermind of the murder was never found.

A charismatic speaker, he had criticised Putin's annexation of Crimea from Ukraine in 2014 and regularly took part in opposition protests. He was 55 at the time of his death.

Nearly a decade earlier, in 2006, the killing of journalist Anna Politkovskaya outside her Moscow home shocked the world.

Politkovskaya, a reporter at Novaya Gazeta, Russia's top independent newspaper, was a fierce critic of Russia's brutal tactics in Chechnya.

Five people were jailed in connection with the murder, of whom one -- a former policeman -- was pardoned in November 2023 after he fought in Ukraine.

- Jailed -

Other critics have been jailed, most recently Orlov, a key figure of the Nobel Prize-winning Memorial group which he co-founded to commemorate the victims of communist repression.

The 70-year-old was accused of discrediting the Russian army in a column written for the French online publication Mediapart criticising the war in Ukraine.

Opposition politician Vladimir Kara-Murza, 42, was jailed for 25 years in April 2023 in the harshest sentence so far over comments critical of the Kremlin and the Ukraine offensive.

He was charged with treason, spreading "false" information about the Russian army and being affiliated with an "undesirable organisation".

He suffers from serious health problems which his lawyers say were due to two poisoning attempts in 2015 and 2017.

Opposition politician Ilya Yashin was jailed for eight-and-a-half years in December 2022, for spreading "false" information about the Russian army, also under legislation criminalising criticism of the Ukraine offensive.

In July 2023, Lilia Chanysheva, an associate of Navalny in the central Bashkortostan Republic, was handed seven-and-a-half years in prison for "extremism."

In December, a court sentenced Ksenia Fadeyeva, who led Navalny's now-banned organisation in the Siberian city of Tomsk, to nine years in jail for "extremism".

- Exiled -

Some of Putin's high-profile critics have been living in exile for years.

They include former oil tycoon Mikhail Khodorkovsky, who spent a decade in prison after challenging the Russian leader early in his rule and now lives in London.

The decision in February 2022 to send troops into Ukraine, which ushered an unprecedented crackdown at home on critics, dealt a knockout blow to Russia's opposition.

Russians opposed to the invasion are now scattered around the world, including numerous journalists from independent media outlets that have been branded "foreign agents".