In an exclusive interview, Gen Budanov has said Western nations are providing “priceless” intelligence support by locating the launch sites of Russian missiles fired at Ukraine. 

The spymaster, whose office complex works in semi-darkness as all the windows are barricaded with sandbags and has a canary in a cage to warn of a possible Russian gas attack, also said “special agencies from western countries” are helping track down Russian spies searching for the weapons supplied by Nato and other countries.

Asked about partisan attacks inside Russia, Gen Budanov, who has survived 10 known assassination attempts, said: “It’s clear that during the war, intelligence is responsible not only for gathering data, but also conducting special operations. 

“Working with big groups of people - you can call them partisans - is just a small part of our activities.

“We help them, support them and interact with them, sometimes we ask them to perform some tasks.”

He also said his wife, Marianna Budanova, is getting better after being poisoned last year with heavy metals in an attack widely thought to have been carried out by a Russian special operations unit.

Gen Budanov said he knows who was responsible for the attack and offered the following threat: “These kinds of things need some time to be resolved. In time everybody will see what that means.”

Watch Dominic’s video analysis above. Find more episodes of Defence in Depth on The Telegraph’s YouTube channel.