Two French auction houses that intend to sell dozens of pre-Hispanic artifacts are facing allegations of selling fakes by Mexico's official archaeological institute.

A majority of 46 supposedly Mesoamerican pieces to be sold separately by the Joron Derem and the Binoche et Giquello auction houses are of recent creation, Mexico's National Institute of Anthropology and History, or INAH, said in a statement released Monday.

INAH said it conducted a "thorough investigation" of the pieces, which include sculptures and masks made of stone and clay, all of them supposedly made by civilizations that inhabited the Mesoamerican region in the Pre-Columbian period.

Joron Derem was scheduled to auction seven of these pieces yesterday, while Binoche et Giquello plans on auctioning 39 other pieces on June 18. An estimated 65 percent of those pieces are fakes, INAH said.

The remaining 16 pieces were determined to be original and of value to the Mexican people, which prompted INAH to declare the agency will file a lawsuit in an attempt to get them back. Neither house in France has responded to the INAH statements.

Mexico has been called as a "paradise for archaeological looting," and the INAH estimates that about 40 percent of the country's registered archaeological sites have been robbed.

According to Jorge Sanchez Cordero, an INAH specialist, the institute does not have updated lists of archaeological thefts, which further complicates efforts to tackle the issue. Mexico is one of the countries with the highest number of archaeological thefts in Latin America, experts say.

"We need people who specialize in our cultural assets, but unfortunately we don't have them," Sanchez said in an interview last October.

The sale of Pre-Columbian pieces is a common practice both legally and illegally, and a glimpse at the catalogue of famous auction house Sotheby's shows that it remains a profitable business.

The estimated price for a small Pre-Hispanic humanoid figurine from the state of Guerrero, Mexico, is valued at between $9,000 and $12,000 dollars. And a figure of a Mayan lord is expected to fetch a price of $150,000 dollars.

This isn't the first time that possibly fake pieces from Mexico are up for sale. In 2014, the Bonhams auction house in New York intended to sell a batch of Pre-Hispanic pieces, but the INAH determined that half the items were recent copies.