The reason there seems to be little evidence is because nominees are intentionally kept secret for 50 years.
From the Nobel Prize site (emphasis added):
Are the nominations made public?
The statutes of the Nobel Foundation restrict disclosure of information about the nominations, whether publicly or privately, for 50 years. The restriction concerns the nominees and nominators, as well as investigations and opinions related to the award of a prize.
Everyone involved in the nomination/selection process is restricted from disclosing it.
Of course, people suck at rules, so there are naturally anecdotes about who was nominated. The problem then is sorting that out from the wild speculation that also happens.
The sources given by Wikipedia are in Italian, so I can't assess their accuracy very well. I found another source:
...In 1995 his name was even put forward for the Nobel Prize for Poetry, but the committee proved insensitive to his literary merits, despite letters of recommendation from the Dante Alighieri Prize Committee, presided over by Cardinal Silvio Oddi, the Ministry of Culture of the Kyrghyz Republic, the director of the Literary Institute of Uzbekistan and the Senate of the University of Oradea in Romania. ...
but it claims that he was nominated in 1995, and lists different supporters. This is not to say that both couldn't be true, but I don't believe you're going to find hard evidence either way.