Earlier this month, a wooden carving of the Hawaiian god of war fetched $7.5 million at a Christie's auction in Paris.
The huge price tag, twice what curators expected, made international headlines.
But now some are wondering whether the Kukailimoku is authentic.
"In my opinion and maybe a few academics, the piece is not genuine," said Mark Blackburn of Honolulu, who has collected Polynesian artifacts for decades.
Meanwhile, Adrienne Kaeppler, curator of Oceania at the Smithsonian Institution National Museum of Natural History in Washington D.C. and formerly with Bishop Museum in Honolulu, said in an email to Hawaii News Now that while she wasn't involved in the sale "as far as I know it has not been authenticated."
Christie's said in a statement, though, that the work was "extensively researched."
"A thorough history was published in our printed catalog and online prior to sale," Christie's said. "We stand by our cataloging and research."
The carving went to an anonymous private collector.
Christie's said the statue, which is 21 inches tall, was created for King Kamehameha I sometime between 1780 and 1819.
"When I first saw this figure I was astonished — really speechless," said Susan Kloman, head of African and Oceanic Art at Christie's, in a marketing video. "We couldn't imagine that such a work could still exist in a private collection."
But Blackburn said authentic statues of Ku on heiau were much taller than people at 9 to 12 feet tall.
He examined the sculpture in Paris this September and said it's small.
"The size, the stance, the wood, lack of sex on it and most importantly, it had not been authenticated by the three world experts on this type of thing," he said.
He believes the piece is a copy and said many were carved and sold during the monarchy of King Kalakaua, who died in 1891.
Blackburn has a copy of the Ku carving from that period, which he purchased from Christie's for few thousand dollars.
While Christie's issued a statement, it did not answer specific questions about the sculpture's authenticity.
In the video, Kloman said the auction house's authentication process was really to analyze it through the Morellian method, analyze it through every detail how this work was carved."