A Russian journalist known for her critical coverage of the war in Chechnya was shot to death on Saturday, her body discovered in an elevator in her apartment building in Moscow, officials said.

Anna Politkovskaya, a tireless investigative reporter, had written a critical book on Russian President Vladimir Putin and his campaign in Chechnya, documenting widespread abuse of civilians by government troops.

Her body was found in an elevator in her Moscow apartment building, a duty officer at a police station in central Moscow told The Associated Press. Dmitry Muratov, editor of the Novaya Gazeta newspaper, where Politkovskaya worked, told Ekho Moskvy radio that she was killed in the late afternoon.

The Interfax news agency, citing police officials, reported that Politkovskaya had been shot and that a pistol and four bullets were found in the elevator.

"Whenever the question arose whether there is honest journalism in Russia, almost every time the first name that came to mind was Politkovskaya," said Oleg Panfilov, director of the Moscow-based Center for Journalism in Extreme Situations.

Panfilov also said that Politkovskaya had frequently received threats, and that a few months ago unknown assailants had tried unsuccessfully to break into the car her daughter Vera was driving.

Prosecutors planned to open a murder investigation into the death, said Svetlana Petrenko, spokeswoman for the Moscow Prosecutor's Office.

In 2001, Politkovskaya fled to Vienna for several after receiving e-mail threats alleging that a Russian police officer she had accused of committing atrocities against civilians, was intent on revenge. The officer, Sergei Lapin, was detained in 2002 based on her allegations but the case against him was closed the following year.

Politkovskaya began reporting on Chechnya in 1999, during Russia's second campaign there, and concentrated less on military engagements than on the human side of the war. She wrote long, empathic stories about the Chechen inhabitants of refugee camps and Russian soldiers she found in hospitals — until she was banned from visiting those hospitals, Panfilov said.

More than any other Russian reporter, Politkovskaya has chronicled killings, tortures and beatings of civilians by Russian servicemen — reports that put her on a collision course with the authorities.

"There are journalists who have this fate hanging over them," Panfilov said. "I always thought something would happen to Anya, first of all because of Chechnya."

Politkovskaya fell seriously ill with symptoms of food poisoning after drinking tea on a flight from Moscow to southern Russia during the school hostage crisis in Beslan in 2004, where many thought she was heading to mediated the crisis. Her colleagues had suggested the incident was an attempt on her life.

She was one of the few people to have entered the Moscow theater where Chechen militants took hundreds of hostages in October 2002 and try to negotiate with the rebels.

Politkovskaya's death was the highest profile killing of a journalist in Russia since the July 2004 slaying of Paul Klebnikov, editor of the Russian edition of Forbes magazine.