When Russia's best known political prisoner, Mikhail Khodorkovsky, was released last month from prison after serving almost all of his 10-year sentence, he told reporters "you should not see me as a symbol that there are no more political prisoners left in Russia."

The former oligarch, who was once Russia's richest man — until he ran afoul of the Kremlin and had his sprawling oil and gas company taken over by state businesses —  said he would devote himself to helping free the many other political prisoners still languishing in remote penal colonies.

Watch Defying Putin, directed by Susan Teskey, on CBC TV's Doc Zone, tonight at 8 p.m.

It could be a big task.

The long run-up to the Winter Olympics in Sochi, which begin next week, has seen a widespread crackdown against Vladimir Putin's political opposition, a crackdown that was initiated almost two years ago following the mass street protests against Putin on the eve of his presidential inauguration.

What's more, according to the international organization Human Rights Watch, despite the Kremlin's release in December of some high-profile prisoners, among them Khodorkovsky and two members of the feminist punk group, Pussy Riot, political repression has in fact expanded.

"Many serious problems plague Russia's human rights record" said Tanya Lokshina, Russia program director at Human Rights Watch in Moscow.

Among them, she noted the new anti-gay law, which forbids any public promotion of "non-traditional sexual relationships," and the Kremlin's enforcement of its "foreign agents" law, which targets hundreds of non-governmental groups on suspicion of spying.

RUSSIA-KHODORKOVSKY/SENTENCE

Former oil tycoon Mikhail Khodorkovsky stands in the defendants' cage during a court session in December 2010, when he was sentenced to six additional years for theft and money-laundering. He was amnestied by Putin in December 2013. (Reuters)

An equally effective way of muzzling the political opposition, though, has been the Russian court system which, critics say, has been manipulated to prosecute what some see as fabricated criminal cases.

"When authorities are at war with society, one of the tools used for political purposes is criminal repression," says Alexander Cherkasov, head of the Memorial Human Rights Centre in Moscow.

Memorial which was founded by the physicist and famous dissident, Andrei Sakharov — maintains an ongoing list of people it considers "political prisoners," meaning those arrested largely for taking part in demonstrations or other opposition activities.

There are 41 names on the list at the moment, although Memorial says these are only the scrupulously documented cases, and that the actual number of political prisoners is much higher.

In its report, Human Rights Watch describes how, on the same day that Khodorkovsky was being released and flown to Berlin, a Russian court quietly sentenced Evgeny Vitishko, an activist who chronicled environmental damage in Sochi, to three years in a penal colony.

The Kremlin also used the court system, critics say, to try to silence the irrepressible Alexei Navalny, Russia's best known political activist and a thorn in Putin's side.

The 38-year-old Navalny rose to prominence in 2011 as an outspoken blogger who published articles about government corruption on his independent website.

He then became the face of the opposition movement in the winter of 2011-2012, and famously branded Putin's gang, "the party of crooks and thieves," a slogan that stuck and which may have made the Kremlin determined to crush him.

Perhaps not by coincidence, investigators in the provincial city of Kirov charged Navalny with embezzlement, reviving a five-year-old, discredited investigation. They claimed he stole $500,000 worth of timber when working for the regional government.

Navalny's trial this past summer was all over the international media, who were intrigued by his raw courage and irreverent sense of humour (he tweeted to supporters throughout the court proceedings) in the face of what he routinely claimed were trumped-up charges.

Russia's conviction rate in criminal cases is a staggering 99 per cent, and even Navalny knew he was doomed. Sure enough, the Russian court found him guilty and sentenced him to five years in prison.

As he was being led away to his jail cell, Navalny sent one last irreverent tweet to his supporters: "Don't miss me. Main thing, don't be lazy!"

RUSSIA-NAVALNY/

Anti-corruption blogger Alexei Navalny and his wife Yulia won a rare victory in July when he was accepted as a candidate in the Moscow mayoral election, something he saw as a stepping stone to challenging Vladimir Putin for the presidency in 2018. However, he was defeated in September by the Kremlin-backed candidate. (Grigory Dukor / Reuters)

Earlier, he had told the court, "Every time someone thinks 'Why don't I step aside and wait?' he only helps this disgusting feudal regime which, like a spider, is sitting in the Kremlin."

No one knows why exactly that the court quickly released Navalny, slapping him instead with a suspended sentence and barring him from public office.

In any event, his odyssey is chronicled in a new CBC Doc Zone documentary, Defying Putin, directed by Susan Teskey, who filmed him and two other political mavericks this summer.

In the process, she gained unusual access to a Russian courtroom and two election campaign war-rooms. 

"The kind of trials we observed clearly undermine the integrity of the justice system," says Teskey.

"Because people convicted of serious crimes are banned from running for political office, they can be used to eliminate political threats. And they create a climate of fear for anyone who has independent views."

Although Navalny's story is among the most prominent in Russia, it is echoed across the country. Teskey also travelled to Yekaterinburg to film Aksana Panova, 30, a smart and fast-talking editor of an independent web publication in the Urals city.

Aksana Panova

Aksana Panova, editor of a web publication in the Urals city of Yekaterinburg was charged with a series of criminal offences after taking on government corruption in her city. (CBC)

Panova was met with the same legal attack after her publication took on government corruption in her own city.

The regional governor took over the web agency, and then brought charges against Panova for extortion, money laundering and embezzlement. If found guilty, she would face 15 years in prison.

"It's not a real trial. It's theatre", says Panova in the documentary, talking inside the courtroom in Yekaterinburg. "They don't like people with independent opinions."

Putin's regime has gradually extinguished the independent media, and television broadcasting is now controlled by the Kremlin. The internet is the only, albeit powerful, medium for anti-Kremlin voices.

In Defying Putin, Teskey also interviews a twenty-something supporter of Navalny, Tatiana Volkova, a young scientist, who was initially devastated but also politically motivated by his sentencing.

Navalny's trial was "purely political," she says. "That's why no person can be neutral, because the next day could be him."