A fourth-century papyrus manuscript containing the long-lost 'Gospel of Judas' will be presented in Washington on Thursday .

The Gospel of Judas is one of several ancient accounts of Christ's life which were rejected as suspect by the fathers of the early Church and so they did not become part of the Bible .

Vatican officials have denied that the publication this week is part of a rehabilitation of Judas by the Catholic Church .

The document reportedly argues that Judas Iscariot, known to Christians as the man who betrayed Jesus Christ, was an essential part of God's design and, as such, almost a hero .

Without his betrayal, Jesus would not have been crucified and so, the argument goes, God's plan to save mankind from its sins would not have been fulfilled .

The papyrus containing the text of the 'gospel' appeared about 30 years ago on the Egyptian antiquities market. It had last been heard of in AD180, when Saint Irenaeus, a bishop, condemned it as heretical .

It was recently acquired by the Swiss-based Maecenas Foundation for Ancient Art and the U.S.-based National Geographic magazine, who are behind this week's publication .

The text, which has been translated into English, French and German, is written in Coptic, the language used in Egypt when the country converted to Christianity halfway through the third century AD .

The text was the work of an ancient Gnostic sect called the Cainites, which made a habit of giving a positive value to all the negative figures in Christian scriptures .

It is believed to have been originally written in the first or second centuries. The text was later copied onto the papyrus which is to be presented in Washington .

The forthcoming publication has sparked fears among some in the Catholic Church that it could give people wrong ideas about the man who is famous for betraying Jesus Christ .

"Some people will try to hide the truth and give undue importance to a document written in the 2nd century by people in open opposition to the early Christian Church," said a Rome-based theologian who is an expert on ancient texts .

Experts say the manuscript is interesting and important for scholars of Church history but changes nothing in the accepted view of Judas .

Italy's top Catholic writer, Vittorio Messori, noted however that the text does raise interesting questions about the role of Judas in the Christ story .

Interviewed by the Turin daily La Stampa, he noted that a key difference between the Gospel of Judas and the Bible accounts concerns the question of forgiveness .

Messori recalled that in the apocryphal account Judas is forgiven: "He weeps, Jesus forgives him and in order to purify him he sends Judas into the desert to do spiritual exercises." In the New Testament, in the Gospel of Mark, Jesus is quoted as saying: "Woe to that one by whom the Son of Man is betrayed! It would have been better for that one not to have been born." After the betrayal, they never meet again and, overcome with remorse, Judas commits suicide. Christ atones for the sins of humanity but never specifically forgives Judas .

Messori said the lack of forgiveness in the Bible account appeared strange in a man who preached forgiveness .

He also noted that Jesus's choice of Judas as a disciple in the first place seemed to show a slip of judgment .

But, as someone who wanted to believe the Gospels were true, he said he was glad of Judas's presence. "If the gospels had been invented, the figure of Judas just wouldn't be there because he's so embarrassing," he said .