Bart D. Ehrman on pg. 280 said:
One of the most widely disseminated modern forgeries is called The Unknown Life of Jesus Christ. From this account we learn that Jesus went to India during his formative teen years, the “lost years” before his public ministry, and there learned the secrets of the East. The book made a big splash when it appeared in English in 1926; but as it turns out, it had already been exposed as a fraud more than thirty years earlier. The reading public, it is safe to say, has a short attention span.
The book was first published in France in 1894 as La vie inconnue de Jésus Christ, by a Russian war correspondent named Nicolas Notovitch. Almost immediately it was widely disseminated and translated. In one year it appeared in eight editions in French, with translations into German, Spanish, and Italian. One edition was published in the United Kingdom, and three separate editions in the United States. The book consisted of 244 paragraphs arranged in fourteen chapters. Notovitch starts the book by explaining how he “discovered” it. In 1887, he was allegedly traveling in India and Kashmir, where he heard from lamas of Tibet stories about a prophet named Issa, the Arabic form (roughly) of the name Jesus. His further travels took him to the district of Ladak, on the border between India and Tibet, to the famous Tibetan Buddhist monastery of Hemis. While there he heard additional stories and was told that written records of the life of Issa still survived.