Xiang Xiang, who may have fallen from a high place while fighting with wild pandas for food or territory, “suffered rib fractures and internal damage,” the report said, citing the Wolong Giant Panda Research Center in Sichuan.

Xinhua said the long delay in announcing Xiang Xiang’s death was attributed to the need for a full investigation.

“We are all sad about Xiang Xiang, but it doesn’t mean the project has failed,” Zhang Hemin, the center’s head, was quoted as saying. “The lessons we have learnt from what happened to Xiang Xiang will help us adapt and improve the project.”

The 176-pound male panda was released from Wolong in April 2006 and had been trained almost three years to survive in the wild. Xiang Xiang, whose name means auspicious, learned how to build a den, forage for food and mark his territory, experts at Wolong have said. He also developed defensive skills like howling and biting.

According to Li Desheng, deputy director of the Wolong center, Xiang Xiang’s case shows that proves that wild panda communities are reluctant to accept male outsiders.

“We chose Xiang Xiang because we thought that a strong male panda would have a better chance of surviving in the harsh natural environment,” Li was quoted as saying. “But the other male pandas clearly saw Xiang Xiang as a threat. Next time we will choose a female panda.”

State media last year said that Xiang Xiang hesitated for a second when the door of his cage was opened, then scampered off into a nearby bamboo forest where he was tracked by a global positioning device attached to his collar.

He has been buried at the foot of a mountain, about 13 kilometers from the Wolong center, Li said.

There are only about 1,600 wild pandas in the mountain forests of central China, the only place in the world they are found, and more than 180 live in captivity.