CNN  — 

A painting bought at a garage sale in Minnesota is a previously unknown portrait by Dutch artist Vincent Van Gogh, according to a newly published expert analysis.

It was made by Van Gogh during his stay at a psychiatric hospital in the south of France in 1889, experts commissioned by art research firm LMI Group International have said after analyzing the canvas weave, paint pigment and other characteristics.

Acquired by an antiques collector in 2016, the painting bears an inscription of the word “Elimar” in the bottom right corner.

Measuring 45.7 centimeters by 41.9 centimeters (18 inches by 16.5 inches), experts identified the painting as a Van Gogh following a process that took four years.

The oil on canvas painting is a portrait of a fisherman with a white beard, smoking a pipe as he repairs his net.

It is based on a painting by Danish artist Michael Ancher (1849-1927), according to LMI, and is one of many of Van Gogh’s “translations” of works by other artists.

Researchers also found a hair embedded in the canvas and sent it to be analyzed. Although it was found to be from a human male, efforts to match its DNA with descendants of Van Gogh were thwarted by its “degraded state,” said LMI.

“By integrating science and technology with traditional tools of connoisseurship, historical context, formal analysis, and provenance research, we aim both to expand and tailor the resources available for art authentication based on the unique properties of the works under our care,” said Lawrence M. Shindell, chairman, president and chief executive officer of LMI Group, in a press release this week.

Despite the exhaustive analysis, the painting still needs to be attributed to Van Gogh by the Van Gogh Museum in Amsterdam, the Netherlands.

The museum previously refused to attribute the painting to Van Gogh when approached by the previous owner in December 2018.

However, LMI, which acquired the painting in 2019, is confident that it is genuine.

“The discovery of a previously unknown van Gogh painting should come as no surprise,” reads the report. “It is well-known that van Gogh lost many works, gave away works to friends and was not particularly careful about any work he considered a study, of which there were many.”

LMI said in the release that the painting “is an emotionally rich, profoundly personal work created during the final and tumultuous chapter of van Gogh’s life.”

The Dutch master produced some 900 paintings during his lifetime. He is thought to have suffered from a combination of bipolar and borderline personality disorder, though these illnesses were never diagnosed.

In 2020, researchers from The University Medical Center Groningen, in the Netherlands, said that they believed Van Gogh experienced two brief psychotic episodes, presumed to be delirium caused by alcohol withdrawal, following his admission to hospital after cutting off his own ear with a razor in 1888.

Van Gogh died by suicide in 1890 at the age of 37.