Washington, Feb. 21 : Native American chief and hero Geronimo's descendants are suing Skull and Bones, a secret society at Yale University with ties to the Bush family, alleging that its members robbed his grave in 1918 and have kept his skull in a glass case.

The claim is part of a lawsuit filed in a federal court in Washington this week, the 100th anniversary of Geronimo''''s death, the Scotsman reports.

The Apache warrior''''s heirs are seeking to recover all his remains, wherever they may be, and have them transferred to a new grave at the headwaters of the Gila River in New Mexico, where Geronimo was born and wished to be interred.

"I believe strongly from my heart that his spirit was never released," his great-grandson Harlyn Geronimo, 61, said.

Geronimo died a prisoner of war at Fort Sill, Oklahoma, in 1909.

A tradition among members of Skull and Bones holds that Prescott Bush - the father and grandfather respectively of George HW and George W Bush - broke into the grave with classmates during the First World War and made off with the skull, two bones, a bridle and stirrups, all of which were put on display at the group''''s clubhouse in New Haven, known as the Tomb.

The story gained some validity in 2005, when a historian discovered a letter written in 1918 from one Skull and Bones member to another saying the skull had been taken from a grave at Fort Sill along with several pieces of tack for a horse.

Ramsey Clark, a former US attorney-general who is representing Geronimo''''s family, acknowledged he had no hard proof the story was true, but hoped the court would clear up the matter.

Tom Conroy, a spokesman for Yale, declined to comment on the lawsuit, but was quick to note that the Tomb was not on university property.

Members of Skull and Bones, who guard their organisation''''s secrecy, could not be reached for comment.

Geronimo, whose given name was Goyathlay, put up fierce resistance to white settlers, fighting the Mexican and US armies for nearly three decades. He finally surrendered, with only 35 men left, to General Nelson Miles on the New Mexico-Arizona border in 1886 and spent the rest of his life in prison, dying of pneumonia.

It was the Mexicans who named him Geronimo, after a battle in which he repeatedly attacked Mexican soldiers with a knife, ignoring a deadly hail of bullets, in reference to the Mexicans'''' plea to Saint Jerome ("Jeronimo!"). The name stuck.(ANI)