As a major exhibition of ancient Mayan art opens this week in Texas at the Kimbell Museum, a swirling controversy has developed over who owns what in the way of priceless archeological treasures of the Americas.

Does the British Museum -- a major lender to "The Blood of Kings: A New Interpretation of Maya Art" -- rightfully own the six fabulous carved limestone lintels hacked from temples at the jungle site of Yaxchilan in the 1880s at the request of the English adventurer Sir Alfred Percival Maudslay?

Or do they belong to Mexico, as claimed by the director of the Institute Nacional de Antropologia e Historia (INAH), who oversees all antiquities in his country?

The lintels, returning to this hemisphere for the first time since Maudslay had them floated down the Usumacinta River and shipped to London, their imagery of writhing serpents and bloodletting scenes. The six deeply carved reliefs of kings and their consorts, standing four feet tall and three feet wide, once rested above temple doorways in 8th-century Yaxchilan, a site -- temala border currently under excavation by Mexican archeologist Roberto Carcia Moll.

Art historians often equate the Yaxchilan lintels with the Elgin Marbles taken from the Athens Acropolis in the 18th century. The British Museum holds those, too, despite requests from recent Greek governments that the marbles be returned.

Last March 6, just as the British Museum prepared to send its Mayan treasures to Texas, The Times of London published an article in which INAH Director Enrique Florescano was quoted as saying that Mexico wants its lintels back. The interviewer, John Carlin, then went on to add in his own words: "The Mexican government would like to explore diplomatic channels . . . Should that fail, the British Museum should perhaps steel itself for a possible theft attempt."

Carlin then referred to an incident a few years ago in which a manuscript pertaining to the Indian heritage of Mexico was stolen from the Bibliothe que National in Paris, and flown to Mexico City, where the patriot-thief then turned himself in. The manuscript remained in Mexico.

This week, Florescano decried such measures, and said instead that he hoped his country could work out a bilateral treaty with Great Britain on the restitution of cultural objects. "Other treaties have been successful in the short run," Florescano noted. To date, Mexico and the United States have worked out a diplomatic solution on ownership of a set of pre-Columbian murals from Teotihuacan, Mexico, which had ended up in the Palace of the Legion of Honor in San Francisco. The murals now reside in both Mexico City and San Francisco under joint custody.

The British Museum has received "no formal notification from the Mexicans that they want the Yaxchilan lintels back," said British Museum press officer Ewan Balfour from London. "We are very conscious of the article in The Times, but we are taking no extra security measures." The Kimbell Museum has obtained extra protection, in addition to indemnification by the U.S. government, by requesting a legal "Declaration of Immunity From Public Seizure," which prevents claims by third parties on cultural objects imported into the United States for the purpose of exhibition. Such a declaration is frequently sought by the museum for important shows, said Emily Sano, who made the Kimbell's arrangements for "The Blood of Kings" exhibit.

"Actually, in this case, the Rijksmuseum voor Volkenkunde in the Netherlands asked us to do it," Sano said. "The Leiden Plaque in their museum is the most famous piece of Maya jade, and we are very pleased to get it for the show."

The carved plaque was probably worn as a ceremonial ax head attached to the belt of an Early Classic Mayan ruler about the year 320. It was long purported to have been found in Honduras, but epigraphers -- scholars who decipher carved inscriptions -- have found on it what they believe is a version of the emblem glyph of Tikal, Guatemala, possibly opening up claims of ownership from that country.

Such deciphering of the Mayan texts carved on stone and jade and painted on ceramics is the special contribution of "The Blood of Kings" exhibition. Curated by art historians Linda Schele of the University of Texas at Austin and Mary Miller of Yale University, it is the first pre-Columbian art show that is based on breakthrough historical information gleaned from the glyphs in the past 15 years.

During that period a small group of scholars has produced long lists of Mayan rulers who lived between A.D. 250 and 900, after which the Classic Mayan centers declined and their pyramids were covered by encroaching jungle. From the texts and portraits left behind have emerged the names of such kings as Bird Jaguar IV of Yaxchilan, Pacal of Palenque, and Yax Pac of Copan. To Linda Schele, one of the key scholars in the deciphering of the Mayan glyphs, "these rulers are the Tutankhamens, the Alexanders, the Ashurnasirpals of the Americas."

Along with deciphering the long-enigmatic hieroglyphs, the exhibition presents all the iconographic details of Mayan courtly life and religion, based on ritual objects such as jade axes, funeral pottery, clothing and the ornate headdresses of Mayan carving. Mayan artists seldom depicted ordinary people, concentrating instead on the elite who ruled the pyramids and temples and conducted religious ceremonies, most involving personal bloodletting by the kings.

For the show, museums in the United States, Europe and Honduras have lent priceless treasures of America's medieval civilization: rare polychrome pottery from Dumbarton Oaks; a carved panel depicting the ball game played by pre-Columbian Indians from the Art Institute of Chicago; and delicate Jaina tomb figurines from the Princeton Art Gallery, Princeton University. Because of the rarity and condition of many of the artifacts, exhibition lenders would allow the show to travel to only two places. It will appear at Fort Worth from May 17 to Aug. 24 and at the Cleveland Museum of Art from Oct. 8 to Dec. 14.

Yet of all the 110 magnificent objects, none has been lent by the three principal countries where the Mayas originally flourished: Mexico, Guatemala and Belize.

"Belize agreed to lend, then had to back out," said the Kimbell's Sano. "They had already lent out many objects and wanted to keep their best things for their Independence Day celebration this summer." Mexico turned down the Kimbell's request for some of the best objects in the Museo Nacional and instead offered replicas or lesser pieces from the museum storeroom, Sano said. "Guatemala simply said no."

One factor in the Guatemalan refusal may have been the possession by the Kimbell and Cleveland Museums of twin Mayan carved monuments called steles, said to be from Guatemala, brought out of the jungles in the 1970s. Many other U.S. museums hold archeological artifacts with a similarly cloudy past. For the decades that witnessed the growth of Mayan scholarship have also seen an unprecedented wave of mechanized looting of archeological sites throughout Central America. Despite policy statements by museums and scholars condemning the traffic in illegal artifacts and international efforts by UNESCO and other agencies to protect archeological sites, hardly a show on pre-Columbian art could be mounted anywhere without charges that it contains looted material.