MOSCOW — A military correspondent for Russia’s top business daily died after falling from a fifth-story window, and some press outlets speculated yesterday that he might have been killed for his critical reporting.

Ivan Safronov, the military affairs writer for Kommersant, died Friday in the fall from a window in the stairwell of his apartment building in Moscow, according to officials. His body was found by neighbors shortly afterward.

Safronov, who had served as a colonel in the Russian Space Forces before joining Kommersant in 1997, had angered authorities with his critical reporting and was repeatedly questioned by the Federal Security Service, the main KGB successor agency, which suspected him of divulging state secrets. No charges were ever filed because Safronov was able to prove his reports were based on open sources, Kommersant said.

With prosecutors investigating the death, Kommersant and some other press outlets suggested foul play.

“The suicide theory has become dominant in the investigation, but all those who knew Ivan Safronov categorically reject it,” an article in Kommersant said yesterday.

According to the newspaper, the 51-year-old’s hat was found on the landing between the fourth and fifth floors, along with a spilled bag of oranges. His apartment was on the third floor.

The paper cited neighbors and other residents of the building as hearing nothing unusual at the time of the incident, around 4 p.m. Friday.

Safronov’s colleagues and relatives have described him as a strong, cheerful person who would be extremely unlikely to kill himself.