Putin was speaking after talks with German Chancellor Angela Merkel in Dresden and on the day that Politkovskaya was buried in Moscow.
Before Politkovskaya was laid to rest this afternoon, more than 1,000 people filed past her coffin to pay their last respects to a journalist who gained international prominence for her defense of human rights and her criticism of the government's policies, in particular its conduct of the war in Chechnya.
No high-ranking Kremlin or government officials were seen at the ceremony, which was attended by U.S. Ambassador William Burns.
The president of the Russian National Association of Television and Radio Broadcasters, Eduard Sagalayev, said one of the causes behind Politkovskaya's death was a "deficit of truth" in Russia. "If there were no such deficit, if there were more opportunities to tell the truth, to express different points of view about what goes on in the country, perhaps there would be fewer such tragedies," he said, referring to the dozen journalists killed in recent years in Russia.
Politkovskaya was gunned down in her Moscow apartment building on October 7.
Commentators and colleagues from the newspaper "Novaya Gazeta" believe her killing was connected to her work.
In a statement that came three days after the murder, Putin promised a thorough investigation. He also conveyed the same message to Merkel, the German chancellor said after their meeting.
(compiled from agency reports)