Two Russian citizens have claimed to be secretly working for Ukrainian intelligence agencies.
They also described actions they said targeted military targets, military equipment and military personnel inside Russia.
We are calling one of these people Ivan.
Ivan claims that while living in Russia, he played a role in Ukrainian drone attacks that targeted Russian strategic bombers and weapons factories.
Ivan appears in a BBC World Service documentary. This documentary is about people who secretly carry out such actions within Russia.
Russia's military officers are monitored
This documentary has been made by independent Polish journalist Marcin Mamon.
There is also another person in the documentary, who we are calling Foma. Foma is from Russia, but currently lives in exile in Poland.
Foma says he runs a network of volunteers working secretly in Russia.
According to him, people of this network keep an eye on senior military officers of Russia. These are the officers whom Ukraine's military intelligence agency GUR is considering targeting.
However, Foma insists that his men were not themselves involved in any attacks.
Foma also did not reveal which officers his men were monitoring.
But after the assassination of Lieutenant General Fanil Sarvarov in Moscow in December last year, he admitted that he had given information about the general to Ukraine.
There have been media reports in the past about groups carrying out such covert operations in Russia. But it is very difficult to reach someone like Ivan, who is living and working in Russia, and tell about his alleged activities.
GUR has confirmed that both Ivan and Foma work for them.
But the agency has also admitted that it cannot know the complete information.
Many political assassinations in Russia after the war started
The officer with whom Ivan remains in contact in the Ukrainian intelligence agency GUR was asked whether he had complete confidence in Ivan. To this he said, "I don't trust anyone except myself."
GUR, Ivan and Foma are very careful about how much information they share.
Because of this it is not possible to independently verify the actions in which both of them claim to have been involved.
However, the broader methods that Ivan and Foma describe have been accepted by Ukrainian authorities.
The government of Ukraine has explained its strategy for joint drone attacks inside Russia.
Ukraine says that legitimate targets are targeted in these attacks. The government has also admitted that secret agents are used for such operations.
By the way, many political assassinations have also taken place in Russia since the war started.
Ukraine's policy is to neither officially acknowledge its role nor take responsibility for attacks targeting specific individuals.
However, a Ukrainian intelligence official previously admitted to the BBC that Ukraine was behind the assassination of senior military officer Lieutenant General Igor Kirillov in December 2024.
How many Russians are working for Ukraine?
It is difficult to find out how many Russian citizens are doing this kind of work for Ukraine.
Foma claims that the number of such people is between 300 to 500. However, it is not possible to confirm this.
Ivan and Foma say they are not just against Russia's war in Ukraine. They also oppose the government of President Vladimir Putin.
He believes that Putin's political future depends on the outcome of the war.
"At this point I think if they lose the war, Putin's government could fall," Ivan says.
“Through our actions we are trying to speed up this process.”
Ivan told Marcin Mamon that his job also included keeping an eye on military targets.
He also used to look for a place to hide the drone parts. All this was done to prepare for possible attacks on Russian military bases and equipment.
"When these drone parts are put together, it becomes a very powerful weapon," Ivan said.
"It can destroy something worth millions of dollars in a single attack."
Ivan sent Mamon a video. In this, he was allegedly seen hiding explosives near a military airport in Russia.
Had he been caught, he would have been charged with terrorism and could have been sent to prison for decades.
How does Foma's network work?
Foma's work is different from Ivan's.
He trains his volunteers online while staying out of Russia.
Marcin Mamon saw him giving one such training.
During this time Foma was telling his volunteers how to track down the senior military officer they had been asked to keep an eye on.
"You will receive a file from me or one of my colleagues. It will contain the name of the person to keep an eye on," Foma told his volunteers.
"The file will contain their photograph, personal details, date of birth, age and appearance. If they have a car, details of that will also be there."
"When you go to that person, don't take the phone with you."
Foma says he was once part of Russia's powerful and influential class.
That's why he has some special contacts, from whom he keeps getting inside information.
Foma shows Mamon on his laptop how he maps the locations of military bases and people.
"It is a collection of information. It gives the locations of warehouses storing goods and military units," he said.
"It also includes where the generals live and where the pilots of the strategic bombers that bombed Ukraine live."
"To break a system you have to understand how it works. Then you can target its weak spots."
Foma said that there are about 36 people in his network.
These people live in Russia, Ukraine and other countries of Europe.
People outside Russia help in delivering goods and making other arrangements.
They also trace the online activities and information available on the Internet of people who may be targeted.
Foma stressed that GUR suggests the names of people to keep an eye on.
But he and his team also investigate at their own level whether the person should be considered a military criminal or not.
“Normally we also check the information related to that person,” Foma said.
“Only after that we decide whether to work on it or not.”
Foma considers his team's actions correct.
"I want those who are doing terrible things in Ukraine on behalf of Putin and Russia to understand that they will pay a price," he said.
'I want them to be scared'
Foma stressed that he only provided information to Ukraine. His network itself does not kill anyone.
Foma sent a message to Mamon after the assassination of General Sarvarov in December 2025.
In it he wrote, "It took a lot of effort to keep track of them."
"He sometimes lived with his girlfriend and sometimes with his partner. He hid his scars and constantly changed his schedule."
However, Foma did not share any of its plans with Mamon or the BBC before taking this action.
Russia's largest military drone factory attacked
Ivan provides little information about his work.
Even after any incident, he used to avoid telling things related to it.
Foma gathered information about Ivan on his own.
He spoke to military intelligence sources in Ukraine and Russia.
After this, Foma felt that Ivan might have been involved in the plan to attack Russia's largest military drone factory in June last year.
This factory is in Yelabuga.
There was news of one person being killed in this incident.
Ivan stressed that such actions always seek to protect civilians from harm.
But these actions have also been very dangerous for Ivan.
"The most serious incident happened when my car was stopped for security check and I had hand-made explosives," he said.
"The risk was too high. But as you can see, they couldn't catch me."
Do not leave your mark on the Internet
Ivan explained that there is no clear organizational way to do this to reduce the risk of someone getting caught or the entire system being exposed.
He said he has never met the other people he works with. He doesn't even know their identity.
Foma also adopts the same rules for his people.
"As soon as you start gathering people into groups or shared online chats and leaving your mark on the Internet, there is a very high chance that the entire group will be quickly arrested or eliminated," he said.
'There are very few people left in Russia for this work'
Ivan said that there are very few people left in Russia who can do this kind of work.
He said, "Most of the people working on the basis of ideology have either left the country or are in jail."
According to the information received by BBC, many people involved in such actions while living in Russia do not know what work they are becoming a part of.
For example, some truck drivers may not realize that the goods they are carrying have been tampered with.
Some other people do such work for money.
But Ivan says that he is doing this work because of his ideology. He was previously a member of the political opposition.
For this reason, it is expected that Russian officials will keep a close eye on his activities.
So it was surprising that he managed to escape from Russia and then return several times.
How does Ukraine trust Ivan?
Marcin Mamon invited Ivan to accompany him to the desert area of Georgia. There both could talk openly.
Mamon asked Ivan how Ukrainian officials could trust him.
This allegedly showed that Ivan works for him.
The two conversed in sign language and mentioned "repairs at the school."
But Ivan's liaison officer later admitted that he could not completely rule out the possibility that Ivan might be working for Russia either on his own free will or under duress.
Foma believes that Ivan's ability to travel easily is not in itself a reason to doubt him.
He told Mamon, "There are all kinds of weaknesses in the country's system."
“If you know about them or are just lucky, you can bypass those paths and stay in that system.”
"It's like a mouse finding its way between the holes in a piece of cheese."
'Putin will not live forever.'
Another thing seems more important.
If Ivan had also been spying for the FSB, Russia's security agency, there was a possibility that he would have given the Russian agency his information related to plans for attacks in Ukraine.
More than a year before a massive and devastating attack by more than 100 Ukrainian drones, Ivan was telling Marcin Mamon about a major attack on strategic bombers based at various Russian military air bases.
However, he never specified when and where the attack would take place.
Mamon asked Ivan how he coped with the pressure of this job.
"Fear is always present. It follows me everywhere," Ivan said.
"You're still scared even if you're not doing anything. This is Russia."
But Ivan was hopeful that his life would eventually change.
And then Ivan said, "Putin won't live forever."
