Auctions like this "strip these unique and priceless goods of their cultural, historic and symbolic essence, turning them into merchandise or mere novelties," Mexico’s National Institute of Anthropology and History said.
Mexican experts that 51 of the 130 pieces billed as being from Mexico are "archaeological pieces that belong to the nation" and the rest are recently made handicraft pieces.
On 8 March the institute asked France to halt the sale, without explaining why it wants the 59 pieces that it says are not antiques to be withdrawn.
On 27 February Peru told the AFP news agency that it judged 60 pieces to be part of its heritage and demanded restitution and Guatemala claimed 13 pieces ealier this month.
The sale of the collection of Swiss national Jean Paul Barbier-Mueller is estimated to be worth about 20 million euros and is likely to attract massive attention from collectors of Latin American traditional art.
The art dating from before the Spanish conquests in Latin America was previously housed in Barcelona but negotiations for the sale to the city fell through partly because Barbier-Mueller insisted that no other pieces be added to it, for fear that they might not be genuine, and partly because of the economic crisis that has hit Spain.
Barbier-Mueller insists that all his pieces were acquired from reputable dealers who vouched for their authenticity and their provenance.
Sotheby's says that all the pieces at auction on 22-23 March were acquired before the convention came into effect.
"The Barbier-Mueller Collection is world-renowned for its remarkable works of art, its ownership by a distinguished collecting family and its long history of public exhibition," the auction house told RFI by email. "Sotheby’s has had dialogue with several nations and given careful consideration to their concerns about this sale and we continue to welcome discussion regarding any new information on specific issues.
"Over the course of the past six months, Sotheby’s thoroughly researched the provenance of this collection and we are confident in offering these works for auction."