Written by Matthew Robinson, CNN

Art experts may have solved a riddle that has been baffling them for years: whether a drawing of a nude woman, bearing a striking resemblance to the Mona Lisa, is a Leonardo da Vinci original.

Following extensive testing, investigators from the Center for Research and Restoration of the Museums of France (C2RMF) say the charcoal drawing, known as the "Monna Vanna" or "Nude Mona Lisa," was completed in da Vinci's studio and may have been the work of the master himself.

The drawing was previously thought to have been completed by da Vinci's students.

Experts at the center found that much of the work was completed by a left-handed artist, supporting theories that da Vinci was the creator.

Left-handed charcoal marks hint at da Vinci's involvement. Credit: Christophel Fine Art/UIG via Getty Images

Mathieu Deldicque, the curator of the Condé Museum, which has housed the drawing since 1862, said in a statement that the analysis had revealed "lots of new elements," including "left-handed charcoal marks pretty much everywhere."

They also found that the drawing featured da Vinci's preferred "sfumato" technique, a process of blurring color transitions, concluding that the piece was not a copy of a lost original.

"There is a very strong possibility that Leonardo did most of the drawing," Deldicque said. "It is a work of very great quality done by a great artist."

"It is almost certainly a preparatory work for an oil painting," he added.

Suggestions by experts that the drawing could be an original reemerged in 2017, when Bruno Mottin, a conservation expert at the Louvre, confirmed that it dated from the same period as da Vinci's lifetime.

He believed, however, that it was completed by a right-handed person, thereby ruling out da Vinci.

Deldicque said Mottin was thrown by "hatching on the top of the drawing near the head done by a right-handed person," which analysis has revealed may have been added at a later point.

'Nude Mona Lisa' could be work of da Vinci

Despite the renewed fascination with the drawing, Deldicque warned that experts must "remain prudent" and be "serious and scientific" about attributing the work to da Vinci.

He admitted, that despite "the quality of the drawing, both under the naked eye and under imaging analysis," experts may never be "absolutely certain" about its origins.

In June, the Monna Vanna will form the centerpiece of an exhibition at the Condé Museum in Chantilly, northern France, commemorating the 500th anniversary of da Vinci's death in 1519.

The exhibition will bring together many replicas of the "Monna Vanna" by other artists and compare them alongside the original Chantilly sketch.