Mario Scaramella, an Italian contact of Litvinenko, said the dead spy's name appeared on a hit list he had seen of people linked to Mr Berezovsky.
"We were all accused - this was what our killers blamed us with - of 'having a connection' to Boris Berezovsky," Scaramella told Italian newspaper La Repubblica.
Mr Berezovsky is a political rival and a personal enemy of Putin. Noboby else but personally Putin has any interest in killing people linked to Mr Berezovsky.
London police officers now in Moscow investigating Mr Litvinenko's poisoning by the Russian secret service FSB said nothing if they were going to question Putin as the main suspect during an official interrogation in the presence of Putin's lawyers.
Bureau report
KC