Klimt's Portrait of Miss Lieser fetches $49m at auction

Gustav Klimt's Portrait of Miss Lieser, a painting of a young woman left unfinished when the Austrian artist died, has sold at auction despite open questions about its subject and previous ownership.

The work was long thought to have been lost when in fact it was hanging in a private villa near Vienna for decades, according to the auction house Im Kinsky that put it on display in January before putting it under the hammer at which it sold for 30 million euros ($A49 million).

Im Kinsky had estimated its value at 30 million to 50 million euros.

It shows its likely teenage subject in a turquoise dress draped in a flowing floral gown against a red background, her alabaster skin and piercing, pale brown eyes contrasting with her dark, curly hair.

Despite depicting her so clearly, it remains unclear who "Fraeulein Lieser" actually was.

The brothers Adolf and Justus Lieser were wealthy industrialists in the Austro-Hungarian empire, having built their wealth on jute and hemp, making twine and rope.

Henriette Amalie Lieser-Landau, nicknamed "Lilly", was married to Justus until their divorce in 1905 and became a well-known patron of the arts.

It is possible she commissioned the painting of one of her daughters, or Adolf Lieser could have done so with his daughter Margarethe as the subject.

"According to the latest provenance research, Klimt's model was possibly not Margarethe Constance Lieser, Lilly Lieser's niece, but one of her two daughters (with Justus), either Helene, the older one, born in 1898, or her sister Annie, who was three years younger," the auction house said on its website.

What happened to the painting after Klimt's death in 1918, when it would have been in his studio, remains unclear, particularly what happened after Nazi Germany annexed Austria in 1938 and the country's Jews were persecuted, expropriated and sent to concentration camps.

Margarethe left Austria for Hungary and then the United Kingdom but the auction house says the painting verifiably never left Austria.

Lilly Lieser stayed in Vienna until she was deported in 1942 and then killed in Auschwitz the following year.

Her daughters returned to Vienna after World War II to reclaim her assets but the painting was not mentioned in any documents, Im Kinsky said.

"It was these many ambiguities and historical gaps that prompted the current owners to contact the legal successors of the Lieser family and to agree on a 'fair and just solution' with them all in 2023," Im Kinsky said, without identifying the current owners.

"It has been agreed not to disclose the contents of the said agreement; however, it can be stated that all conceivable claims of all parties involved will be settled and fulfilled through the auctioning of the artwork," it said.

"The agreement essentially means that - from a purely legal point of view - it is immaterial who commissioned the painting from Gustav Klimt and which of the three young ladies in question it portrays."