Lev Ivanov was the lead investigator in the Dyatlov tragedy. He worked for the prosecutor's office of the Sverdlovsk region (the city in which the nine hikers lived and attended the Ural Polytechnic Institute). Most likely he was sending messages to his boss, a man named Klinov. Not sure about him keeping maps privately. I believe he did keep in his possession some of the last photos taken the night of Feb. 1 by several of the hikers. These photos showed strange objects in the night sky. After his death, his daughter made them public.
In a 1990 interview, Ivanov stated his belief that UFOs were the cause of the hikers' mysterious exit from their tent. That would account for radiation. He believed the three hikers who suffered fatal injuries were targeted and murdered by a UFO.
Conspiracy theories abound. Perhaps one of the hikers who worked in a nuclear facility was going to pass secret documents or photos to Soviet operatives of the CIA. Sasha was not known by any of the hikers when he asked to join the hike. They could find no reason to say no to him. He was formerly in the Soviet military and was a very skilled hiker/skier. Sort of a mystery man, so obviously, a number of conspiracy theories point to him.