The Horse & Rider piece, which the artist created circa 1508, features French military governor Charles d’Amboise – Da Vinci’s friend and benefactor – on his horse.

The statue, crafted from a block of solid beeswax, will be unveiled at the Greystone Mansion in Beverly Hills on 27 August (12). The art piece will then tour the world this autumn (12), with stops planned in London, New York, and Las Vegas.

Event spokeswoman Nadine Jolson tells WENN, “For over 25 years, the owner has kept the irreplaceable mold safe and carefully pondered its future. He is now ready to share his masterpiece with the world and raise money to help people in need.”

The mold owner, businessman Richard A. Lewis, has joined forces with longtime art broker Rod Maly and certified fine art appraiser Brett Maly to create an unprecedented limited edition offering of the sculpture to the public. Lewis has agreed to donate $1 million (£625,000) to The Salvation Army based on sales of the edition.

Speaking about the history of the piece, Jolson explains, “The beeswax study was presumed to be a model for a larger, never-completed monument of the governor. After his death in 1519, Leonardo’s star pupil, Francesco Melzi, inherited the sculpture along with the rest of Leonardo’s effects. It is believed to have remained with his family, in Italy, until the 1930s when it was taken to Switzerland, for safekeeping, as war broke out.

“In 1985, a group of businessmen traveling to Switzerland was shown the hand-carved sculpture in beeswax. Intrigued, they contacted the foremost authority on the life and works of Leonardo, Dr. Carlo Pedretti, to authenticate the work. Following a thorough examination of the beeswax, on July 10, 1985, Professor Pedretti proclaimed in writing, ‘In my opinion, this wax model is by Leonardo himself,’ and dubbed the one-of-a-kind sculpture Horse and Rider.

“Based on the authentication, they decided it was imperative to create a mold from the delicate wax sculpture to preserve the work and honor the artist’s intent.

“Fascinated with the story and importance of the discovery, Mr. Lewis, an engineer and real estate businessman, took possession of the original mold of Horse and Rider in New York, along with all the supporting documentation. Twenty-five years later, the mold was restored and cast in bronze at one of the country’s oldest and most revered fine arts foundries, The American Fine Arts Foundry in Burbank, California.”