RENEE MONTAGNE, host:

Journalists at a leading Russian newspaper say a colleague might have been killed for his investigative reporting. Ivan Safronov fell to his death from his apartment building last Friday. At first the authorities said his death was probably a suicide.

But as NPR's Gregory Feifer reports from Moscow, they have agreed to look into the case.

GREGORY FEIFER: Prosecutors launched an investigation after an outcry from Safronov's colleagues. Some of the circumstances surrounding his death have raised suspicions. Safronov apparently fell from a fifth-floor stairwell of his apartment building, a bag of groceries and his hat were found scattered on the stairs below.

Sergey Dyupin, a colleague of Safronov's at the Kommersant Newspaper, says he can't be sure, but Safronov wasn't the kind of person you'd expect to kill himself.

Mr. SERGEY DYUPIN (Kommersant Newspaper): (Through translator) He was a very jolly, open, self-assured person. And he had a sober view about life and its problems. I can't find any reason he'd want to commit suicide.

FEIFER: Ivan Safronov became a military reporter in 1997. Before that, he'd been a colonel in the Russian space forces. Kommersant said Safronov was working on a story alleging Russian plans to sell weapons to Iran and Syria, via Belarus. Safronov told his editors he'd been threatened with criminal action if he exposed the possible plan to sell highly-advanced Iskendar-E surface-to-surface missiles to Syria. That would almost certainly provoke an angry reaction from Washington, because the missiles would be capable of hitting targets inside Israel.

But Kommersant reporter, Dyupin, who is investigating Safronov's death, says he's found no evidence pointing to murder. And military analyst Alexander Golts says it's unlikely the level of information in Safronov's reports would have prompted his killing.

Mr. ALEXANDER GOLTS (Military Analyst): (Through translator) It's a question of just how crazy the authorities have become, and how far they're willing to go. I don't think we're there yet. Safronov's reports did not pose a life-or-death question for the officials involved.

FEIFER: The Russian Union of Journalists disagrees and is launching its own investigation into Safronov's death. Oleg Panfilov, of the Center for Journalism in Extreme Situations, says Safronov was probably murdered.

Mr. OLEG PANFILOV (Center for Journalism in Extreme Situations): (Through translator) Weapons sales always involve huge amounts of money. The people in our government structures care far more about money than human life.

FEIFER: Safronov had angered the authorities in the past. Last December he reported on the failure of a highly-touted new intercontinental missile. According to Kommersant, the Federal Security Service had investigated Safronov for divulging state secrets, but didn't file criminal charges after he proved his reports were based on open sources.

Safronov's death comes after the murder of prominent investigative journalist Anna Politkovskaya last October, seen by many reporters as a warning in a country one media watchdog says is the second most dangerous for journalists after Iraq. The Brussels-based International News Safety Institute says 88 journalists and media staff have been killed in Russia in the past decade.

Gregory Feifer, NPR News, Moscow.

MONTAGNE: All this week on ALL THINGS CONSIDERED, Gregory Feifer looks at how Russia has evolved in the Putin era. You can learn more at npr.org. Transcript provided by NPR, Copyright NPR.