Originally Published: 14 JUN 23 06:00 ET

Updated: 27 JUN 23 14:43 ET

By Oscar Holland and Jacqui Palumbo, CNN

(CNN) — The last portrait completed by Gustav Klimt became the most expensive artwork ever to sell at a European auction Tuesday, when it sold for a staggering £85.3 million ($108.4 million) in London.

Depicting an unidentified female subject, “Dame mit Fächer” (Lady with a Fan) also established a new record for Klimt, outselling “Birch Forest,” which fetched $104.6 million last year from the collection of the late Microsoft co-founder Paul G. Allen. The bidding on Tuesday lasted 10 minutes before going to an unidentified buyer in Hong Kong, according to Sotheby’s auction house.

“Dame mit Fächer” was one of two paintings found at the Austrian artist’s studio upon his death in 1918, according to Sotheby’s.

A work the artist had started a year prior, in 1917, “Dame mit Fächer” is rendered in Klimt’s characteristically rich, expressive style. Like much of his output, it showcases the East Asian influences that shaped his work — not only in the fan held by his unknown sitter, but also the use of phoenix and lotus blossom motifs. The background’s flattened perspective meanwhile evokes the Japanese wood-block prints that featured prominently in the painter’s sizable Asian art collection.

Sotheby’s had dubbed the portrait Klimt’s “last masterpiece,” with the auction house’s head of impressionist and modern art evening sales, Thomas Boyd Bowman, describing it ahead of the sale as “stunning.”

“The beauty and sensuality of the portrait lies in the detail: the flecks of blue and pink which enliven the sitter’s skin, the feathery lines of her eyelashes and the pursed lips that give her face character,” he said in a press release.

Most of Klimt’s best-known works — including his iconic “The Kiss” — emerged from his earlier “Golden Phase,” in which he often incorporated gold leaf into his art. This period of his career was finished by the turn of the 1910s. But Klimt was, at the time of this death aged 55, in his “artistic prime and producing some of his most accomplished and experimental works,” Sotheby’s head of impressionist and modern art Helena Newman said in a statement.

“Dame mit Fächer” is one of the few Klimt portraits still in private hands. Unusually, it is square-shaped, measuring roughly one meter (3.3 feet) in both height and width. Newman also noted that — unlike many of Klimt’s best-known portraits — the work was not a commission, meaning it was likely painted for his own pleasure.

“This … is something completely different — a technical tour de force, full of boundary-pushing experimentation, as well as a heartfelt ode to absolute beauty,” she said.

The painting was previously owned by Viennese industrialist Erwin Böhle, a friend and patron of Klimt’s. It was later purchased by art collector Rudolf Leopold, who sold it to the current owner’s family at Sotheby’s in 1994 for $11.6 million — at the time, a new auction record for the Austrian artist. The painting has not appeared at auction since, though it was exhibited last year at The Belvedere, an Austrian museum housing “The Kiss” and several other important Klimt works.

Klimt’s paintings have exploded in value over the last two decades. The Austrian is now among only a handful of artists whose works have sold publicly for nine-figure sums.

Other works are thought to have sold privately for even more. According to the Financial Times, court documents from an ongoing legal dispute between the Russian billionaire Dmitry Rybolovlev and art dealer Yves Bouvier showed that the oligarch once purchased Klimt’s “Wasserschlangen II” (Water Serpents II) for $183.8 million.

Klimt’s “Portrait of Adele Bloch-Bauer I” was meanwhile bought by US businessman Ronald Lauder for a reported $135 million in 2006. Ten years later, Oprah Winfrey sold another depiction of the same subject, “Portrait of Adele Bloch-Bauer II,” to a Chinese buyer for $150 million, according to Bloomberg.

“Dame mit Fächer” was the star lot in Sotheby’s modern and contemporary art summer auction, which was timed to coincide with the long-awaited reopening of London’s National Portrait Gallery. The auction featured other portraits by prominent artists, including Alberto Giacometti and Edvard Munch.

The sale came amid fears that the auction market is cooling following an initially buoyant recovery from Covid-19. The latest edition of UBS and Art Basel’s annual market report found that global auction revenues, having surged by 47% in 2021, declined by 1% last year.