Carnel Chamberlain's body was found under a wood porch or deck at the home on the reservation of the Saginaw Chippewa Indian Tribe, 70 miles north of Lansing, Kevin Chamberlain said.

Chamberlain, the tribe's former chief, said he had no details about what led investigators back to the house after many days of searching woods, ponds and the tribe's wastewater treatment areas.

The body "had to be in a grave. We had looked underneath before and didn't see anything," he said.

Photos of 4-year-old Carnel Chamberlain, from the Saginaw Chippewa Indian Tribe, hang at the tribal operations building Friday, June 22, 2012. Chamberlain disappeared Thursday. (AP Photo/The Morning Sun, Holly Mahaffey)

Carnel disappeared June 21 while in the care of his mother's boyfriend.

 "There's a lot of anger, just utter despair and disbelief. I don't know how else to define it," said Chamberlain, who is a cousin of Carnel's mother, Jaimee Chamberlain. "After a long week of searching and hoping, we're at a horrific, bitter end."

Tribal police referred calls to the FBI, which declined to comment on the investigation. Any charges in the case would be handled by federal authorities, who have jurisdiction over major crimes on Indian reservations.

Police have said Jaimee Chamberlain's boyfriend was not very cooperative during the weeklong search and has consulted a lawyer.

A vigil attended by Jaimee Chamberlain, other relatives and dozens of supporters was held Thursday night. People sang, played drums and gave speeches urging love and healing in the face of tragedy.

Earlier this week, Jaimee Chamberlain, 21, told The Associated Press that her son was missing when she returned home from work on June 21. Her boyfriend told her Carnel wasn't around.

"I ran inside and looked around. I didn't know what to do," said Jaimee Chamberlain, who went to a neighbor's home to look for Carnel and then called police.

Source: abcnews.go.com