A series of Andy Warhol works commissioned by well-known art collector and Warhol friend Richard L. Weisman was stolen from the owner’s L.A. home sometime on Sept. 3. “The Athletes,” a series of 10 pieces depicting famous sports figures from the 1970s, was discovered missing from Weisman’s dining room by a housekeeper, who immediately called the police. Warhol made a number of sets of the series, which may complicate matters during the search for them. A Warhol portrait of Weisman was also taken.

An investigation is ongoing, but police have no leads so far. Warhol is one of the top 10 most frequently stolen artists, according to the Art Loss Register. A reward of $1 million is being offered for information that will lead to the art’s recovery.

Read more at the Los Angeles Times.