Japanese researchers said they have discovered an ancient copy of a legendary Buddhist sutra, written in Sanskrit, in the city of Lhasa.

It is the first time in modern history that an original Sanskrit text of the sutra, known as "Yuima-kyo" in Japanese and "Vimalakirti" in Sanskrit, has been discovered, Taisho University researchers said. Buddhists have so far used texts translated into old Chinese and Tibetan.

Members of the Tokyo-based university's Buddhism research institute, which has been studying Buddhist texts in Tibet, found a complete copy of the scripture in July 1999 at the Potala in Lhasa. The copy, which dates back to the eighth century, is very well-preserved, they told a recent news conference.