The Native American Hopi tribe is taking a Paris auction house to court to try to block the upcoming sale of 32 sacred tribal masks.

The Katsinam masks are scheduled for sale at the Drouot auction house on Dec. 9 and 11, alongside an altar from the Zuni tribe and other Native American frescoes and dolls.

Advocates for the Hopis argue that selling the sacred Katsinam masks as art merchandise is illegal because the masks represent their ancestors' spirits.

In April, a Paris court ruled that such sales are legal. Tribal lawyers filed a new lawsuit over the most recent sale, and a Paris court opened proceedings in the case Tuesday.