The looming Paris auction of some 70 ceremonial masks originating from the Hopi tribe of Arizona has cast light on the failure to prevent sacred American artifacts being sold overseas.

Dozens of the striking, brightly coloured kachina visages and headdresses are due to go under the hammer in the French capital on Friday in a sale being staged by Neret-Minet auction house.

But representatives of the southwestern Hopi tribe, who number around 18,000, are appalled by the prospect of a slice of their cultural heritage being touted to the highest bidder.

The Hopi say the items being auctioned are blessed with divine spirits, and insist that even the mere description of them as masks or artifacts is highly offensive, adamant that the upcoming auction is a form of sacrilege.

"The objects that are being auctioned are considered sacred because they are part of our religious beliefs," Hopi president LeRoy Shingoitewa said.

"They are used in a manner that helps us to help our people in this world to get harmony, to get blessings.

"These are not considered among our people to be art," he told AFP. "We want to stop the auction. We want the sacred objects returned back to the Hopi."

The difficulty for the Hopi is that while the sale of sacred Indian artifacts has been outlawed in the United States since 1990 -- legislation which has allowed the tribe to recover items held by American museums in the past -- the law does not extend to sales overseas.

"It is difficult. We are dealing with international law and another government," Shingoitewa said.

"We are a very small tribe. Financially it becomes very difficult. We want to be humble. We are asking that the auction house help us."

A spokesperson for Neret-Minet insists, however, there are no grounds to halt the sale, stressing that the items being sold were acquired legally by a French collector during a 30-year residence in the United States.

Shingoitewa is not convinced.

"If I go into a cathedral and I take a statue of Mary, and go outside and say 'Who wants to buy this from me?' members of that faith would be very upset," Shingoitewa told AFP.

"We want to know who the owner is, how they got to France, the purpose of this individual taking these out of the US and from the Hopi."

James Scarboro, a lawyer representing the tribe, called on Neret-Minet to delay the sale until the provenance of the items could be established.

"If the auction house would have the decency to postpone the auction for a time, so we can get to the bottom of this, I feel at least optimistic that we can resolve it in a friendly way," he said.

US auction houses and curators meanwhile say selling kachina items would be unthinkable as well as illegal.

"We do not offer for sale kachina masks because of the religious sensitivity," said Jim Haas, head of the ethnographic art division at Bonhams in San Francisco.

"Out of respect, obviously, and politically it doesn't make sense for us to have a firestorm of criticism and native people marching outside at our door in protest."

John Molloy, a New York gallery owner, said the US government needed to establish laws which would prevent similar sales in future.

"The United States has to make an issue that other countries shouldn't trade culturally sensitive items," he said.

Despite Neret-Minet's insistence that Friday's sale is legal, Shingoitewa is clinging to the hope that a solution can be found.

"(We) use prayers, use our hearts and hope that the French auction house will have compassion, and be able to say: 'We understand, and we will call off the auction, and we will work to help return the items back to the Hopi people.'"