WASHINGTON (AP) -- National Geographic unveiled an ancient manuscript Thursday that may shed new light on the relationship between Jesus and Judas, the disciple who betrayed him.

The papyrus manuscript was written probably around 300 A.D. in Coptic script, a copy of an earlier Greek manuscript.

It was discovered in the desert in Egypt in the 1970s and has now been authenticated by carbon dating and studied and translated by biblical scholars, National Geographic announced.

Unlike the four gospels in the Bible, this text indicates that Judas betrayed Jesus at Jesus' request.

The text begins "the secret account of the revelation that Jesus spoke in conversation with Judas Iscariot."

The key passage comes when Jesus tells Judas "you will exceed all of them. For you will sacrifice the man that clothed me."

This indicates that Judas would help liberate the spiritual self by helping Jesus get rid of his physical flesh, the scholars said.

The manuscript was first mentioned in a treatise around 180 A.D. by a bishop, Irenaeus of Lyon, in what is now France. The bishop denounced the manuscript as differing from mainstream Christianity and said it produced a fictitious story.

There were several gospels in circulation at the time in addition to the four in the Bible. When those gospels were denounced, it was thought that believers hid them away.

What scholars refer to as the gospel of Judas was kept by a group called the Gnostics, who believed that the way to salvation was through secret knowledge given by Jesus to his inner circle.

National Geographic said the author believed that Judas Iscariot alone understood the true significance of Jesus' teachings.