During cross examination, Pavel Ryaguzov, denied anyone had approached him for information on the investigative journalist's address and twice rejected prosecution claims he had passed the information on Politkovskaya onto those suspected of involvement in the murder.
Politkovskaya, who gained international recognition for her reports of military atrocities against civilians in the troubled Caucasus republic of Chechnya, was gunned down in an elevator in her Moscow apartment building in October 2006, in what police described as a contract killing.
Three men, Dzhabrail and Ibragim Makhmudov, brothers from Chechnya, and former police officer Sergei Khadzhikurbanov have been charged with involvement in the murder.
Giving evidence on Thursday, Khadzhikurbanov said that during the investigation he had been pressured to give a statement against fugitive Russian oligarch Boris Berezovsky in exchange for his freedom.
"Investigator Garibyan demanded that I testify against Berezovsky and promised that he would leave me out of the case," Khadzhikurbanov said adding that he was also asked to give evidence against some high-ranking officials in Chechnya.
Top investigators in Russia earlier claimed that fugitive tycoon Boris Berezovsky, who lives in London, was behind the murder.
The man suspected of pulling the trigger, Rustam Makhmudov - the eldest of the three Makhmudov brothers - remains at large. A separate case has been opened against him.