For several months, opposition protests in Russia have given liberal anti-Putin Russians an opportunity to make their feelings heard. However, it is not just liberals who have been out on the streets but other groups too, including far-right nationalists.

Over the years I have met some pretty hardened Russian men on my travels. Muscular guys, able to handle their drink, and most importantly - fond of a joke.

But rather like the ice in a Siberian winter, there are those who take a far colder, harsher view on life.

They call themselves skinheads - although shaven heads are no longer mandatory.

In recent years skinheads have been held responsible for many of the far right attacks on immigrants across Russia. Many of the perpetrators have been locked up. Some have since been freed.

Maxim is one such former convict. We meet in the garden of a Moscow burger restaurant. We sit not far from the sizzle of beef on a grill, surrounded by the yelping and chanting of children, hyperactive after sugary drinks.

It was not, perhaps, the most appropriate place to meet a notorious ultra-nationalist, one who has done time for incitement of racial hatred. Especially one whose nickname, Tesak, means machete.

Munching on his burger, he made it clear to me that he was angry, fearful and by the looks of his two young, well-built henchmen, possibly quite dangerous.

"I think immigrants should be housed in separate workers' villages," he told me. He went on to explain how he felt they were sponging off society and putting Russian women in danger of attack.

Then he got out his knife.

I looked up at him, expecting a menacing smile. Instead all I saw was mischief. An eyebrow raised as if he had just learnt how to make the gesture - and then he leaned over to his henchmen, whispered something in their ears and they giggled.

"Have you ever had to use it?" I asked, trying to bring him back to the interview.

"I told you not to ask such stupid questions," he said, putting it away. He gave a twitch of the eyebrow to his two bodyguards, who then laughed in that sinister way that does not involve smiling.

The comment took me back to a video I had watched on the internet before setting out. It showed a man - possibly from central Asia or the Caucasus - being dragged through a forest. It's like some dark horror movie, but this is real.

The men I met did not drink, they despised modern, drunken, vodka-shot Russia, they despised Putin

There are screams, which may have been added later. But then, the man is tied up and killed. The details of how he is savagely murdered are too horrific to watch. Those who have studied the video assure me of its authenticity and say the killing is the work of a far-right gang.

No authority seems to have the power or desire to take it off the web.

It is part of the lawlessness of Russia - a country where the armed ultra-nationalists seem to have almost been given free rein to take the law into their own hands.

These men all take the same anti-immigrant view as Tesak, but some are better educated and articulate their campaign more effectively.

Roman is a law student who wants to be a customs officer. In his spare time he gains entry to squalid basements, trying to check the papers of migrants who live there.

Then there is the lawyer, Dmitry, who spends his Sundays away from his family in the countryside with his gun, practising firing at paper targets so that, if it comes to it, he is ready to take on the immigrants.

Image caption Russian President Vladimir Putin has been accused of allowing illegal immigration to rise unchecked

I met the worldly Russian neo-Nazi, Nils, who had studied Nietzsche overseas. He saw himself as quite the uber-human.

In every interview I was trying to understand why these people felt the way they did. I asked myself, "Were they born like this? Would they beat up any non-white person they did not like?"

All of them tried to twist the conversation if they did not like the questions. Smiles would quickly evaporate turning into venomous, dead, serious glares that meant one thing - change the subject.

The men I met had a number of things in common. They did not drink, they despised modern, drunken, vodka-shot Russia, they despised Putin for having, they believe, tolerated multiculturalism.

And they all shared a total lack of irony.

The members of Russia's far right exist in a weird, dark, mysterious world, one they want all fellow Slavs to inhabit.

They may have the power to attract a following of other youngsters through their internet campaigns and sheer street credibility. They may be able to skirt the law to take on someone they do not like. They may be growing as a political force. It is hard to say.

But they do not own Russia. And although many Russians are strongly nationalistic, most of them would never like to let the skinheads have their way.

How to listen to From Our Own Correspondent:

BBC Radio 4: A 30-minute programme on Saturdays, 11:30 BST.

Listen online or download the podcast

BBC World Service:

Hear daily 10-minute editions Monday to Friday, repeated through the day, also available to listen online.

Read more or explore the archive at the programme website.