// BBC WORLD NEWS — MONDO
Inside the shadowy world of anti-Putin sabotage from within Russia
Watch: Russian saboteur working for Ukraine shares reconnaissance videos
Two Russian men secretly working for Ukraine's intelligence services have given rare accounts of operations they claim to have been involved with, that have targeted military assets and personnel inside Russia.
One of the men, whom we are calling Ivan, claims to have played a role from Russia in Ukrainian drone attacks on strategic bombers and munitions factories on his home soil.
He features in a BBC World Service documentary about the shadowy world of Russian saboteurs.
The documentary, by independent Polish journalist Marcin Mamon, also features a man we are calling Foma, a Russian living in exile in Poland.
Foma runs a network of undercover volunteers in Russia, that surveils high-level officers that the GUR - Ukraine's military intelligence service - is considering targeting, he says. He stresses they are never involved in the attacks themselves.
He was also tight-lipped about who they were surveilling, but after Lt Gen Fanil Sarvarov was assassinated in December last year in Moscow, Foma admitted he had provided the Ukrainians with intelligence on him.
Lt Gen Fanil Sarvarov was killed in Moscow last year by an explosive device hidden under his car
There have been previous media reports of Russian sabotage groups, but it is rare to get access to someone operating on the ground, like Ivan, explaining alleged activities.
The GUR has confirmed that Ivan and Foma are both working for the agency. But it also has acknowledged that it cannot know the full picture. When Ivan's handler was pressed on whether he could be trusted, the handler replied: "I'm not sure of anyone, except myself."