Dmitry Sapozhnikov was born and raised in Russian Saint-Petersburg city. He is the head of local Monarchic party office.

In Oct 2014 he decided to go to fight in Ukrainian east to "protect Russians". He was a commander of DNR "spetznaz" unit. Right now he is on his leave in Saint-Petersburg. He participated in battles for Donetsk Airport and Debaltseve.

According to DNR official media it was the "spetznaz" who played the final role in closing the cauldron. Dmitry told BBC that after that his unit was getting ready for an assault on Mariupol.

The interview was done by the BBC over Skype two weeks ago, additional questions were asked personally in St.Pb.

The interview is quite long and I hope BBC translates it themselves in full but here is the interesting part quoting Dmirty:

Let me tell you a little secret. Take Debaltseve for an example. In early Feb we got there, made a base in Uglegorsk. Tried to take the road to Logvinovo, but we were encircled. Lots of Ukrainian troops were there. But then we took Logvinovo because in 3-5 days our tanks came to help. Russian army came to help, buryats. Thanks to them and their heavy tech we won Debaltseve.

From LNR direction russian tanks and army units came. I think that is not a secret, everyone admits that even Russians admit that. There is lots of information online: admitting that Russian forces serve there: multiple army units. So I don't talk about some secret information. Everyone knows that (after coming back to St.Pb. Dmitry was surpised with how little locals know about Russian army involvment - BBC). Thanks to Russian forces we can quickly gain ground. Near Debaltseve we were thinking: "ok, now we'll have to keep them in cauldron for another month or so" but with the help from Russians we won in 3 days.