The Louvre Museum in Paris has discovered three sketches on the back of a painting by Leonardo da Vinci that may be by the Renaissance master himself.

The drawings -- of a horse’s head, a skull, and the baby Jesus with a lamb -- are barely visible to the naked eye. They were found behind “The Virgin and Child With St. Anne” by a team examining the Louvre’s Leonardo paintings using state-of- the-art technology, the museum said in an e-mailed press release.

So far, no back-panel drawings by Leonardo have been known to exist, the Louvre said. While the style of the three sketches recalls Leonardo’s, the team is pursuing its research to determine their exact origin, the release said.