The source said that Ruslan S., who may be in question, is 35 years old.
The interlocutor, who had known the suspect for a short time, said that Ruslan was fond of politics, wore camouflage, often lived in forests and hitchhiked.
A number of media outlets reported that the suspect had been detained. There is no official confirmation of this.
Earlier, the Investigative Committee opened a case under articles on a terrorist attack and the illegal acquisition of explosive devices on the fact of the derailment of 19 train cars in the Ryazan region.
* Alexei Anatolyevich Navalny is included in the register of individuals involved in terrorism and extremism.