A descendant of a Native American civil rights pioneer is calling on Harvard University to turn over a tomahawk once owned by his ancestor.

In an interview with GBH All Things Considered host Arun Rath, Brett Chapman of Oklahoma said that Harvard’s Peabody Museum of Archaeology and Ethnology is in wrongful possession of the tomahawk, which once belonged to Chief Standing Bear of the Ponca Tribe.

In 1879, Standing Bear became one of the first Native Americans granted civil rights under U.S. law, when he successfully sued for a writ of habeas corpus in a federal court in Nebraska after being held in custody by the United States Army.

Chapman said that after his victory, Standing Bear gave the tomahawk to one of his lawyers, John Lee Webster, in gratitude. The tomahawk’s path from Webster to Harvard is somewhat unclear, but Chapman said he believes that Webster wrongfully gave away an heirloom.

“He [Standing Bear] was so thankful to these attorneys. He viewed them basically as family,” Chapman said. “My objection here is on a moral basis. Standing Bear had no idea that what he thought was family was just going to give away this relic.”

No matter how the tomahawk made its way to the Peabody Museum, Chapman said it's incumbent on Harvard to turn it over. Chapman said he’s been in touch with others who want the museum to return the tomahawk.

“The Ponca tribe of Nebraska, they want it back too,” Chapman said. And in a post to Twitter this week, Chapman said he’s been told that the Nebraska state legislature is planning to introduce a resolution calling for the tomahawk’s repatriation.

Chapman has made direct appeals to the Peabody Museum to turn over the tomahawk, recently writing to museum director Jane Pickering. Pickering replied, saying in part, “We would welcome the possibility of dialogue with you, other lineal descendants, and tribal government representatives.”

Chapman isn’t satisfied with Pickering’s response. In a written statement to GBH News after the All Things Considered interview, Chapman said “I want to ‘collaborate’ and have an immediate ‘dialogue’ about the specific things I addressed in my letter regarding this tomahawk, nothing more. The author failed to address the tomahawk at all. That is disrespectful.”

Responding to a request for comment on the matter from GBH News, a Harvard spokesperson said “The Peabody is interested in conversations that could lead to repatriation, but believes that other family members and tribal representatives should be invited to join such discussions. This would be a necessary first step and we would be glad to work with Mr. Chapman to do so.”

The back and forth over the tomahawk comes just over a month after the Peabody Museum apologized for its past refusal to return some Native American relics and human remains to their tribes of origin.