Karen King, a professor at Harvard divinity school, presented the ancient text at a conference in Rome this month, claiming it contained the words ''Jesus said to them, 'my wife','' a possible reference to Mary Magdalene.
Christian tradition maintains that Jesus did not marry, which underpins the Catholic Church's insistence that priests remain single and celibate.
The Vatican made no comment in the days after Professor King's announcement, but L'Osservatore Romano published an editorial on Thursday saying the papyrus was a ''clumsy fake, like many others from the near east'', which had probably been concocted for sale.
The paper's editor, Giovanni Maria Vian, said the story neatly catered ''to a contemporary ideology which has nothing to do with ancient Christian history, or with the figure of Jesus. Either way, in any case, it's fake.''