Pope John Paul's decision to reveal that the 1917 Secret of Fatima foretold the failed attempt to kill him has rekindled the debate over whether the shooting was a communist plot.
"I am 100 per cent certain," said Mr Ferdinando Imposimato, a magistrate who led an investigation into whether the Bulgarian secret services, acting on behalf of the then Soviet Union, had hired a Turkish gunman, Mehmet Ali Agca, to kill the Pope in 1981. "By now, I think there are no longer any doubts," he said yesterday in an interview on RAI, Italian state radio.
"I even wrote to the Pope and I told him that Agca was the instrument of an international plot, which certainly involved the secret services of the East Bloc, among them the Bulgarians and the KGB," he said.
Acting under papal instructions, the Vatican Secretary of State, Cardinal Angelo Sodano, revealed the essence of the Third Secret of Fatima to hundreds of thousands of people at a Mass where the Pope beatified two of the three shepherd children said to have seen the Madonna in 1917 and received her message.
The secret, long feared to be apocalyptic, predicted an attempt to kill a pope and "war waged by atheist systems against the church and Christians" in the 20th century, Cardinal Sodano said.
Agca, a trained killer who was a member of the right-wing Grey Wolves group, shot and nearly killed the Pope in St Peter's Square on May 13th, 1981, the 64th anniversary of the Virgin Mary's first apparition to the Portuguese shepherd children.
At the time of the shooting, events in the Pope's Polish homeland were starting the domino effect that would lead to the collapse of communism in Eastern Europe in 1989.
The Pope was a staunch supporter of Poland's Solidarity union and most historians agree that he had a vital role in events that led to the formation of the East Bloc's first freely elected government and the fall of the Berlin Wall.
The question of who was really behind the assassination attempt is one of the enduring mysteries of the 20th century. It has been the subject of three inquiries and two trials.
Agca, now 41, was arrested in St Peter's Square minutes after the shooting. He underwent a first trial two months later and was given the life sentence he is now serving in Italy.
At a trial in 1986 prosecutors failed to prove charges that Bulgarian secret services had hired Agca on behalf of Moscow.
The so-called "Bulgarian connection" trial ended with an "acquittal for lack of sufficient evidence" of three Turks and three Bulgarians charged with conspiring along with Agca.
But the verdict, a quirk of the Italian judicial system, fell short of a full acquittal. It substantially meant that the jury was not fully convinced of the defendants' innocence but that there was not enough evidence for a guilty verdict.
Agca gave conflicting testimony during the 1986 trial. He said the order to kill the Pope came from the Soviet embassy in the Bulgarian capital, Sofia, but his credibility was damaged when he claimed to be Jesus Christ.
Vatican officials do not like to talk about the possibility of a Soviet-backed plot to kill the Pope but many, including the late secretary of state, Cardinal Agostino Casaroli, often said they were convinced that Agca could not have acted alone.
The Pope first saw the Secret's contents, which the Vatican said is symbolic rather than detailed, after his 1978 election. He has ordered it to be published along with a commentary to help the faithful understand it.