Researchers have partially restored one of the earliest known versions of an Old Testament book.

A team at the University of Kentucky has "virtually unwrapped" the ancient En-Gedi scroll and found it to be the earliest copy of a Pentateuchal book ever found.

The scroll contains verses from Leviticus, researchers said, that were printed on five complete wraps of the animal skin.

Opening the document would destroy it so the team used a process to build a master image of the virtually unrolled scroll containing 35 lines of text, of which 18 have been preserved and another 17 have been reconstructed.

The text is thought to have been destroyed in a fire at a synagogue 1,500 years ago.

"This work opens a new window through which we can look back through time by reading materials that were thought lost through damage and decay," said Professor Brent Seales, who is professor and chair of the University of Kentucky Department of Computer Science.

"There are so many other unique and exciting materials that may yet give up their secrets, we are only beginning to discover what they may hold."