– A Russian journalist who had reported on clandestine Russian paramilitary groups in Syria died Sunday after falling from the balcony of his fifth-floor apartment in Yekaterinburg, authorities said.

The journalist, Maksim Borodin, 32, was hospitalized in a coma after he was found sprawled below his balcony in the city's Kirov district on Thursday, according to New Day, the local news agency where he had worked. He died on Sunday morning.

Investigators had found the door to his apartment locked from the inside, a police spokesman, Valery Gorelykh, told the local E1 news agency. "Those facts suggest that no one left the apartment and that there were probably no strangers there," he said.

While police are investigating Borodin's death, it is not being treated as suspicious, Russia's Investigative Committee said.

Yet in a country where opposition activists and muckraking journalists are routinely attacked and sometimes killed in connection with their work, that assertion was met with derision in some quarters. The doubters pointed to a telephone call that Borodin made the day before he fell.

In the call, he told a friend, Vyacheslav Bashkov, that there was a man with a gun on his balcony, and that several others in masks and camouflage were lurking in the stairwell leading to his apartment. Bashkov said that Borodin had called back an hour later and said he thought it was a training exercise.

Borodin also reached out to another friend, Yulia Fedotova, about the armed men. But Fedotova urged caution about assigning blame for his death. "Even if some serious people wanted him dead, they would know that a person can survive such a fall," she said.