Moscow (AsiaNews) – An article by Anna Politkovskaya set for publication today cost her her life, this according to Novaja Gazeta, the slain journalist's paper, after the 48-year-old woman was found dead last Saturday in an elevator shot with two gunshot wounds.

Ms Politkovskaya had collected witness accounts and photos on torture and abductions in Chechnya against Putin-backed Chechen Prime Minister Ramzan Kadyrov.

"Today we don't know who killed her," Novaya Gazeta said on its website. "It was either revenge by Ramzan Kadyrov [. . .] or of those who wanted suspicion to fall on the current Chechen prime minister."

In a recent interview, Politkovskaya said that she was a witness in a criminal case against the Moscow-backed Kadyrov, whose security forces have been accused of kidnapping civilians and other abuses. But the journalist, who had two adult children, had crossed many other powerful people, including in the Russian military. Her investigative reporting into the army's mafia-like behaviour and questionably patriotic actions showed that under the cover of the fight against Islamic extremism the military was trying to get back in control of Russia.

Politkovskaya also wrote a book critical of President Vladimir Putin, accused of still having a KGB mentality. She reported touching but documented stories of mothers looking for the bodies of their dead sons killed in Chechnya, relayed accounts of the abuses and bullying by Russian commanders of their troops, and presented evidence of the complicity between army, courts and politicians.

The execution-style killing underscores the increasingly dangerous environment for journalists working in Russia since President Vladimir Putin came to power in 2000, launching a crackdown on media freedoms.

Her death brings to at least 13 the number of journalists killed in contract-style killings and has caused a deep sadness but also unleashed a wave of international condemnation.

Amnesty International has called on the authorities "to investigate her murder thoroughly and impartially". Nicola Duckworth, director of Amnesty's Europe and Central Asia Programme, said: "Russia has lost a brave and dedicated human rights defender, who spoke out fearlessly against violence and injustice, and campaigned tirelessly to see justice done."

The Council of Europe has called for her death to be investigated quickly and convincingly.

Former Soviet leader Mikhail Gorbachev condemned the journalist's killing as "a blow to the entire, democratic, independent press."

In Washington, the US State Department spokesman Sean McCormack said the United States was shocked and profoundly saddened by the murder of a journalist who devoted much of her career to "shining a light on human rights abuses and other atrocities of the war in Chechnya".

So far Russian President Putin has not made any public statement on her death.