IVAN Safronov did not die immediately, despite falling four floors from a window in his Moscow apartment block. According to witnesses, he tried to get to his feet after hitting the ground but then collapsed for the final time.

The police say the death of the well-respected journalist, who worked for the daily Kommersant newspaper, has all the hallmarks of suicide - though they are willing to consider the possibility that he was "driven" to kill himself. But his friends insist he was just not the sort to take his own life. Why should he?

They say he was happily married with children, loved his work and was awash in job offers. On his way home he had bought a bag of tangerines, which lay scattered in the stairwell from which he jumped - or was pushed.

Far from being an individual tragedy, the death of Ivan Safronov will be seen by many as part of a grim trend. The Kommersant reporter is at least the 20th Russian journalist to die in suspicious circumstances since 2000, when Vladimir Putin assumed the Russian presidency. Shot, stabbed or poisoned, the journalists have two things in common: no one has been convicted, or in most cases even arrested, after their deaths. And all of them had angered some part of a Russian establishment which appears to suffer little restraint in dealing with its enemies.

"In Russia, " said Oleg Panfilov, president of the Moscow-based Centre for Journalism in Extreme Situations (CJES), "whenever you are investigating something that could destroy someone else's business, it always generates a reaction - and often it is murder."

A specialist in military matters, Ivan Safronov revealed embarrassing details about the Russian defence programme at a time when the Kremlin is trying to rebuild its great power status. Shortly before his death, he was reported to be working on an expos� of secret arms deals by Moscow with Iran and Syria, something that, if true, would have caused further scandal.

"He covered themes that could provoke a reaction, " Panfilov said.

Political opponents of the Kremlin can end up in jail, like the oligarch Mikhail Khodorkovsky, or in exile, like the equally rich Boris Berezhovsky, or simply vilified and ignored by a media industry whose independence is increasingly being squeezed.

But if you are less well-connected, you could be risking your life.

You may not be safe even if you flee abroad: Britain discovered that fact as the renegade security agent Alexander Litvinenko suffered a lingering, agonising death from Polonium-210 poisoning in a London hospital.

Journalists, however, are particularly at risk. According to a new report from the International News Safety Institute, only Iraq has claimed more journalists' lives than Russia in the past decade.

Though nobody is suggesting that Putin had anything to do with any of the deaths, media organisations around the world have expressed concern at what they call "a climate of impunity". At the very least, he is accused of presiding over a country where it appears the murder of journalists goes unpunished.

Few of the killings are as overtly political as the murder of the internationally-known investigative reporter Anna Politkovskaya, who was gunned down last October at the entrance to her apartment block. In that case it seemed clear that her death was sanctioned by someone powerful who wanted her silenced.

However, most cases are much murkier. They can be seen as a particularly brutal form of punishment for reporters who delve too deeply into Russia's sinister intersection of business, organised crime and the state's legal and security apparatus.

Working for a nationally-known news outlet such as Kommersant might be seen as some protection, though that did not save Politkovskaya or two other journalists who worked for Novaya Gazeta, a fortnightly newspaper. She wrote that it received "visitors every day. . .

who have nowhere else to bring their troubles, because the Kremlin finds their stories off-message, so that the only place they can be aired is in our newspaper".

Pursuing corruption in the provinces can be lonelier and even more dangerous. Two editors of a local newspaper in Togliatti, a carproducing city on the Volga east of Moscow (named after an Italian communist because its first assembly line came from Fiat), were murdered in succession. So was the director of the local TV station.

Death is not the only occupational hazard for reporters who show too much investigative zeal. Around 50 court cases are pursued against journalists every year in an attempt to muzzle them, while some 150 members of the profession are seriously assaulted each year.

Panfilov of the CJES makes a direct link between such intimidation and the presidency. "The problem is with Putin himself, " he said. "He showed his true colours with Politkovskaya's death." In the eyes of many, he appeared dismissive and slow to react.

"Putin takes pleasure in launching verbal attacks on journalists, " Panfilov went on. "It is he who defines the atmosphere in which we work."

And after a journalist is killed the truth is rarely if ever exposed.

The investigation into how and why Ivan Safronov died, like those who went before him, is likely to be quietly closed and an open verdict declared.