The artwork Young Man Holding a Roundel by Italian Renaissance painter Sandro Botticelli in London on December 2, 2020 Photo: AFP

A portrait by Italian renaissance artist Sandro Botticelli is expected to sell for more than $80 million when it goes up for auction at Sotheby's in New York on Thursday.

Young Man Holding a Roundel, believed to have been painted in the 1470s or 1480s, is considered one of Botticelli's finest portraits and is the highlight of Sotheby's Masters Week sale.

"This Botticelli is so much more spectacular in every way than anything we've seen coming to the market," Christopher Apostle, Sotheby's senior vice president, told AFP.

The 58-centimeter-by-39-centimeter painting shows a man in his late teenage years with long golden hair sitting holding a disc featuring a bearded saint.

The roundel, which depicts the saint with his right hand raised, is an original 14th-century artwork attributed to Sienese painter Bartolommeo Bulgarini. 

Art historians suspect that Botticelli depicts a nobleman proudly showing off the earlier artwork. 

"This image symbolizes and exemplifies the Renaissance in Florence. We haven't seen anything like it in my lifetime," said Apostle, describing it as "a masterpiece."

The portrait was handed down through several generations of an aristocratic family in Wales for around 200 years.

Art scholars were unaware of the painting's existence until it first appeared on the market in the early 20th century.

Young Man Holding a Roundel has spent much of the last 40 years on public display since its current owner acquired it in 1982 for just 810,000 pounds ($1.1 million at 2021 rates).

It has appeared at New York's Metropolitan Museum of Art, the National Gallery in London and elsewhere.

Sotheby's says a sale of over $80 million would establish the work as one of the most significant portraits to have ever sold at auction.

The previous record for a Botticelli was set in 2013 when Madonna and Child with Young Saint John the Baptist sold for $10.4 million.

The sale would rank alongside Gustav Klimt's Portrait of Adele Bloch-Bauer II, which sold for $87.9 million in 2006 and Vincent van Gogh's Portrait of Dr Gachet, which fetched $82.5 million back in 1990.

The auction house says Young Man Holding a Roundel is as significant as Botticelli's Portrait of a Man with a Medal of Cosimo the Elder and Portrait of Giuliano de' Medici.

Botticelli, who lived from the 1440s to 1510, is one of the most celebrated painters of the early Renaissance period, but only about a dozen examples of his works survive today.

His best-known works are The Birth of Venus and Primavera.

The Sotheby's sale is also selling one of Rembrandt's 136 biblical paintings.

The Dutch painter's Abraham and the Angels is expected to go for between $20 million and $30 million.

It has been in private collections for 150 years and last sold at auction in 1848, for a mere $64.