Pope John Paul II waves in St. Peter's Square in Rome on April 10, 2003, as a white dove is released in honour of his repeated calls for peace. ((Massimo Sambucetti/Associated Press))

Pope Benedict XVI on Friday attributed a miracle to the late Pope John Paul II, which moves the former pontiff one step closer to sainthood.

Benedict declared that the cure of a French nun who suffered from Parkinson's disease was a miracle.

John Paul is expected to be beatified in Rome on May 1, in an event expected to draw thousands of the faithful.

Beatification allows the candidate to be honoured within his or her diocese, region or religious order. Those proposing a candidate for canonization, the process of becoming a saint, have more conditions to satisfy. A second miracle needs to be attributed to John Paul before he can be made a saint.

The announcement was welcomed by members of the church and friends of the late pontiff.

What does it take to be declared a saint? 1. Investigation: A postulator (advocate) examines the nominee's life, writings, and religious acts. That evidence is presented to the Congregation for the Causes of Saints, a special panel of theologians and cardinals. If the case has merit, they are declared "venerable" — a role model of Catholic virtue. 2. Beatification: The Congregation for the Causes of Saints must verify a miracle before beatification. Miracles are considered as extraordinary events produced by God, acting through others and verified by witnesses. 3. Canonization: The Vatican’s Congregation for the Causes of Saints must be presented with evidence of a second posthumous miracle. The road to Catholic sainthood One miracle at a time P.O.V.: Do you believe in miracles? Take our survey.

"This is a huge and important cause of joy," said Warsaw Archbishop Kazimierz Nycz.

Cardinal Stanislaw Dziwisz, the longtime secretary and friend of John Paul, gave "huge thanks" to Benedict for the decree."We are happy today," he said.

John Paul died in 2005 after almost 27 years in his role. He was succeeded by Benedict.

Just weeks after taking over, Benedict waived the normal five-year waiting period, which essentially put John Paul on a fast track to sainthood.

However, Benedict insisted on a thorough review process.

A Vatican-appointed group of doctors and theologians, cardinals and bishops agreed that the cure of a French nun, Sister Marie-Simon-Pierre, was a miracle because of the intercession of John Paul.

Two months after John Paul's death, the nun claimed she woke up feeling cured of her disease. The nun and the others in her order had prayed to John Paul, who also suffered from Parkinson's.

In a statement issued Friday, the Congregation for the Causes of Saints said Vatican-appointed doctors "scrupulously" studied the case and found that the nun's cure had no scientific explanation.