A U.S. animal rights group on Monday (December 2) filed what it said is the first lawsuit seeking to establish the "legal personhood" of chimpanzees.

The non-profit Nonhuman Rights Project asked a New York state court to declare a 26-year-old chimp named Tommy "a cognitively complex autonomous legal person with the fundamental legal right not to be imprisoned."

The lawsuit seeks a declaration that Tommy's "detention" in a "small, dank, cement cage in a cavernous dark shed" in central New York is unlawful and demands his immediate release to a primate sanctuary.

The lawsuit on Tommy's behalf is among three the group is filing this week on behalf of four chimps across New York. The other chimps are Kiko, a 26-year-old chimp living on a private property in Niagara Falls, and Hercules and Leo, two young male chimps used in research at Stony Brook University on Long Island, the group said.

Tommy's owners, Patrick and Diane Lavery, and Stony University did not immediately return requests for comment. Kiko's owners could not be reached on Monday.

Presented by Adam Justice