Next Tuesday, Christie's will auction off an impressive collection of Indian art, minus two items: federal agents seized two ancient artifacts from the auction house on Friday, having traced them to notorious smuggler Subhash Kapoor, who's said to have smuggled over $100 million in rare artifacts.

According to U.S. Immigration and Customs Enforcement (ICE), special agents in Homeland Security Investigations worked with the Manhattan District Attorney's Office, as well as the Indian government and Interpol, to identify and seize the stolen artifacts, which were included in Christie's catalogue for The Lahiri Collection of ancient and modern Indian and Himalayan art, set to be auctioned off during next week's Asian Art Week.

The artifacts are both sandstone, dating back to the eighth and tenth centuries. The older piece is a panel that depicts Revanta, a minor Hindu deity, with an entourage of three horseback riders, and is valued in Christie's catalogue at $200,000-$300,000. The tenth century piece is a statue of Rishabhanatha, a god of the ancient Indian religion of Jainism; that piece is valued at $100,000-$150,000. As of Friday afternoon, both pieces were still listed in the online catalogue.

Kapoor used to be an art dealer in Manhattan, and owned a gallery on Madison Avenue called Art of the Past, the New York Times reported last year. He was arrested in India in 2011, and American authorities have said that he's the most ambitious antiquities smuggler in U.S. history: he's thought to have smuggled 2,622 items, worth $107.6 million and mostly confiscated in Manhattan and Queens. One Homeland Security official described him as having "basically created a black-market Sotheby’s." Kapoor is awaiting trial in India, and denies that he's done anything illegal.

Through Operation Hidden Idol, ICE is trying to return Kapoor's stolen artifacts to India—the two seized from Christie's are the latest that have been recovered. Museums in Hawaii, Massachusetts, and Ohio have turned over items to the feds, and another 15 museums have identified items from Kapoor but want to see proof of their illegality before turning them over, according to the NY Times.

Manhattan DA Cyrus Vance, Jr. said that "every year, fine art collectors from around the world flock to New York for Asia Week, where they spent a reported $360 million last year on Asian antiquities and art...With high demand from all corners of the globe, collectors must be certain of provenance before purchasing."

A Christie's spokesperson said that the auction house is cooperating with the authorities on their investigation, and said that had they known the items were smuggled, they certainly wouldn't have purchased them.

"Under no circumstance would Christie’s knowingly offer a work of art where there are valid concerns over provenance," the spokesperson said. "Government officials have informed us that the evidence they uncovered...was not publicly available and, therefore, could not have been accessed by Christie’s for vetting purposes. This is one of the difficulties the art market faces in vetting antiquities...These can be difficult issues, and Christie’s has for some time now sought to actively engage with all affected parties to find fair solutions."