A draft report made available Thursday said the commission held that the pope was a danger to the Soviet bloc because of his support for the Solidarity labor movement in his native Poland. Solidarity was the first free trade union in communist Eastern Europe.
It said Moscow was alarmed because "Poland was the main military base of the Warsaw Pact, its main supply lines and troop concentrations were there."
"This commission believes, beyond any reasonable doubt, that the leaders of the Soviet Union took the initiative to eliminate the pope Karol Wojtyla," said a draft of the commission's report obtained by The Associated Press.
Wojtyla was John Paul's Polish name.
The draft has no bearing on any judicial investigations, which have long been closed.
If the commission approves the report in its final form, it would be the first time that an official body had blamed the Soviet Union.
The report also said a photograph shows that Sergei Antonov, a Bulgarian man acquitted of involvement in the May 13, 1981, assassination attempt was in St. Peter's Square when the pontiff was shot by Mehmet Ali Agca.
The Bulgarian secret service was allegedly working for Soviet military intelligence, but the Italian court held that the evidence was insufficient to convict the Bulgarians in the plot.
Agca, a Turk, has changed his story often and investigators said it was never clear who he was working for. He initially blamed the Soviets.
The Interfax news agency carried a denial Friday from Russia's Foreign Intelligence Service (SVR) spokesman Boris Labusov, who said "all assertions of any kind of participation in the attempt on the pope's life by Soviet special services, including foreign intelligence, are completely absurd."
In 1991, then Soviet President Mikhail Gorbachev denied there was KGB complicity.
The Italian report said Soviet military intelligence and not the KGB was responsible.
Antonov's lawyer, Giuseppe Consolo, said the photograph was a case of mistaken identity and the man in the photograph came forward during the investigation as an American tourist of Hungarian origin. Consolo said the photo was not used as evidence in the trial.
"Since Antonov is alive and well in Bulgaria, they should make a comparison with the physical person, not with other photos," Consolo said.
Guzzanti, a member of Premier Silvio Berlusconi's Forza Italia party, said the photo was discarded because the technology of the time couldn't determine if it was really Antonov, but recent computer comparisons with other shots of the Bulgarian show that "there is a 100 percent compatibility."
"We don't believe it's possible to reopen the case against Antonov," Guzzanti told the AP. "We just want to set the record straight."
Agca served 19 years in an Italian prison for shooting the pope and then 5 1/2 years in Turkey for murdering journalist Abdi Ipekci.
He was released from the Turkish prison Jan. 12 but returned days later when prosecutors said he must serve more of his 10-year term for killing Ipekci. He will be released in 2010.
The Italian commission was originally established to investigate any KGB penetration of Italy during the Cold War.
The commission president, Sen. Paolo Guzzanti, said he decided to investigate the 1981 shooting after John Paul said in his book "Memory and Identity: Conversations Between Millenniums" that "someone else planned it, someone else commissioned it." The book came out just weeks before the pope's death in April.
The passage drew immediate interest because during a visit to Poland in 2002, he appeared to put the issue to rest, saying he never believed there was a Bulgarian connection to Agca.
The report said the commission used all the evidence gathered during trials in Italy as well as information given by a French anti-terrorism judge, Jean-Louis Bruguiere. That information apparently stemmed from the French investigation of Ilich Ramirez Sanchez, an international terrorist known as Carlos the Jackal, held in France since his capture in Sudan in 1994.
The report must be approved by the full commission, which meets March 7.