By Katie Stallard, Moscow Correspondent
Russia's federal migration service has introduced civilian patrols as part of a crackdown on illegal immigrants.
Civic-minded citizens in Moscow can now sign up to take part in organised raids of migrant housing and street patrols.
The volunteers are supervised by a migration service official and not allowed to use force, unless in self-defence.
Sky News filmed a raid on a suspected migrant workers' camp in a suburb on the outskirts of Moscow.
The volunteers gathered in a supermarket car park at 6am. It was snowing heavily and the temperature was -10C, but the group seemed enthusiastic as they piled out of their 4x4s to discuss the plan.
We set off in convoy towards the camp along a rough track deep in snow. We were told the area is close to a large open-air market where many of the migrants find work.
Volunteers gather in a car park ahead of a raid
At first sight the camp was little more than a shanty town - a ramshackle collection of sheds and garages, improvised shelters against the depths of the Russian winter.
The patrol fanned out on foot, banging on doors and shouting for the people inside to come out.
Most meekly obeyed, zipping up jackets and pulling on hats as they stepped out into the snow and torchlights.
We saw one man breaking down a door with his shoulder after the occupants refused to open the door - a bewildered-looking man in his underwear was ordered to get dressed and get outside.
For the most part the volunteers were entirely civil and polite, and that was perhaps the most striking feature of what was happening - that these were not skin-headed neo-nazis or right wing extremists - to a person they seemed to be reasonable, educated Russians, who genuinely believe migrant workers have no place in their country.
Statistics suggest that view is not in the minority.
A migrant (left) is led away during a raid
According to the most recent research by the independent Levada Centre, 71% of Russians believe an increase in migration leads to an increase in crime.
Some 65% want the number of migrants in Russia - whether here legally or illegally - to be reduced, and 73% support 'strong measures' to deport those here illegally.
Members of the patrol claimed there was a clear link between migrant workers and crime.
The lead volunteer told us he believed migrants were responsible for the vast majority of local criminal activity.
"99% of crime." He explained, "Most often it is of course guests from the east and from the Caucasus."
Another man gestured to the park behind and said: "There is so much stuff going on. They are stealing, raping, right there in the parks."
But that attitude can leave migrant workers vulnerable to exploitation - leaving them feeling they have few rights and even fewer places to turn if they find themselves in trouble in Russia.
A migrant called Bakia says she had been forced to work as a sex slave
Sky News met an Uzbek woman who was freed in an anti-slavery raid in Moscow last year. She told us she was forced to work as a slave for almost 10 years; cleaning, stacking shelves and serving customers in a shop.
Bakia said she was beaten and made to sleep in a basement, but that she could not escape because her children were being kept in a flat elsewhere.
She was rescued along with her six-year-old son, who she says has health problems linked to malnutrition and damage to his legs from being tied to a radiator.
Bakia says she also had a daughter, Camilla, who was taken from her shortly after the birth but she doesn't know what has happened to her.
She has no papers so it is difficult to verify her claims, but she says she has tried repeatedly to report her daughter missing to the police, and a charity has now taken up her case, but four months after her release, she told us no-one is looking for her child.
Bakia said: "Thank God my son is with me, even though he is disabled. My daughter, my daughter, well if they don't want to do this I will go and look for her myself."
She told us she didn't want to leave Russia without finding her daughter, but that it was very clear they were not welcome here.