Pope John Paul I, who reigned for only 33 days in 1978, will be beatified, putting him on the path to eventual sainthood in the Roman Catholic Church, the Vatican said on Wednesday.

A statement said Pope Francis had approved a decree recognising a miracle attributed to the intercession of the late Italian pope, whose birth name was Albino Luciani.

John Paul I was elected on August 26, 1978 to succeed Paul VI and died unexpectedly on September 28. He was succeeded by John Paul II, making 1978 go down in Church history as the year of the three popes.

His sudden death gave rise to several books that alleged conspiracy theories involving murder and poisoning but they were generally debunked and he is believed to have died of heart attack while sleeping. He was 65.

The miracle in the case of John Paul I is believed to be the inexplicable healing of an 11-year-old girl in Buenos Aires, according to Vatican media.

The Roman Catholic Church teaches that only God performs miracles, but that saints who are believed to be with God in heaven intercede on behalf of people who pray to them.