SEOUL, South Korea — A painting attributed to one of South Korea’s most renowned artists has been declared genuine by state prosecutors, despite the insistence of the late artist herself that it was a fake.

The painting “Beautiful Woman” by Chun Kyung-Ja has been the focus of a bizarre, decades-long dispute over its authenticity, and Monday’s announcement by the prosecutors looks unlikely to end the matter, with Chun’s family vowing to pursue efforts to have it declared a forgery.

Born in 1924 in a small town in the southern part of the Korean peninsula, Chun Kyung-Ja was best known for her paintings of female figures and flowers using vivid primary colors that broke with traditional South Korean styles.

Her works have recently sold at auction for between $700,000 and $1 million.

Before her death last year at the age of 91, Chun repeatedly insisted that “Beautiful Woman” — a 1971 portrait owned by the South’s National Museum of Modern and Contemporary Art (MMCA) — was not one of hers.

“Parents can recognize their children. That is not my painting,” she insisted.

The museum was equally adamant that it was, and in April a prosecutorial probe was launched after one of Chun’s daughters filed a complaint, accusing former and current MMCA officials of hurting the artist’s reputation by promoting the painting as authentic.

But in their report on Monday, the prosecutors found in favor of the museum, citing forensic evidence and the opinion of local art experts.

They also clarified the provenance of the painting, saying it was once owned by the former head of the South Korean spy agency and was appropriated by the government after he was executed for assassinating then-president Park Chung-Hee in 1979.

“We tried to uncover the truth by using all possible technologies available for authentic assessment of arts,” a member of the prosecutors’ team said.

Chun’s family on Tuesday rejected the conclusion and accused the prosecutors of seeking to help the state museum authorities save face.

“The prosecutors conspired with the MMCA to ignore the scientific opinion of a world-class imagery assessment firm and… produced this ridiculous result,” the family’s lawyer said in a statement.

The statement referred to the French imagery analysis firm Lumiere Technology that had earlier estimated the possibility of the painting being authentic at less than 0.0002 percent.

“We wonder if the prosecutors… caved in to political pressure,” the statement said, adding that Lumiere Technology would hold a press conference in Paris on Wednesday to refute the prosecutors’ findings. CBB