Three unfinished sketches by celebrated 20th-century artist Amedeo Modigliani were found hidden in one of his paintings by curators at an Israeli museum in Haifa.

The sketches were found hidden beneath the surface of his famous painting "Nude with a Hat" at the University of Haifa's Hecht Museum. This was an accidental finding and was made possible with the help of X-ray technology. The painting was being examined ahead of an exhibition of his works in Philadelphia.

"Through the X-rays, we are really able to make this inanimate object speak," said Inna Berkowits, an art historian at the Hecht Museum, per The Guardian. "Nude with a Hat" is an unusual painting that features a nude woman with a hat on her head on both sides of the canvas. However, on one side the woman has been painted upside down.

Modigiliani, an Italian-born artist, is considered one of the great Modernist artists. The "Nude with a Hat" painting was one of his early works when he had just moved to Paris from Italy.

His nude paintings always managed to become a centre of controversy and his life was nothing short of extraordinary. His style was influenced by African and Cycladic Greek art.

His paintings would feature slender necks and faces and he would often use both sides of the canvas. Some people claim that he did so to save money on new canvasses.

The artist passed away at the age of 35 penniless. However, his paintings now fetch millions of dollars for their owners. His painting "Nu Couché" or (Reclining Nude), auctioned by Christie's in New York in 2015, was sold for $170.4m (£113m).

"Nu Couché" depicts a dark-haired woman lying naked on a red couch with a blue pillow. The painting was purchased by a buyer who wished to remain anonymous. It was sold under Christie's "The Artist's Muse" special auction for paintings and sculptures from the 1860s to the 2000s.

The last big exhibition of his works was held in 2017 at Genoa's Palazzo Ducale. But the museum had to close the show early after several experts pointed out at that some of the paintings were actually fakes.

$69 million Modigliani nude
A Sotheby's employee discusses the merits of the painting "La Belle Romaine" by Amedeo Modigliani during a preview of Sotheby's Impressionist & Modern Art auction in New York Reuters