The sister of a man whose 3-year-old son was found dead in a septic tank near here said Sunday that the father is devastated and "not yet able to communicate with the public," therefore she has been speaking on his behalf.

Sara Kavanagh, sister of Mark Rogers, issued a press release Sunday.

The body of Loic J.M. Rogers was found Friday night in the tank less than 10 feet from where his father said he vanished two days earlier. An autopsy found the child drowned, Flathead County Sheriff Mike Meehan said.

No one has been charged with a crime. Meehan said that when his investigation is complete, probably in a few days, information will be given to the county prosecutor.

Mark Rogers told law officers that he took his son from the home of a friend to a parked van on Wednesday, after dining in the home. Rogers said he told the child to get into the van, went back to the house for another child and upon returning minutes later, Loic was gone.

Rogers called authorities, who began a search that grew to include dozens of volunteers, the FBI and the U.S. Border Patrol.

The owner of the home, Rogers' friend Tommie Cates, agreed to stay elsewhere Friday night so authorities could search her property, Meehan said.

The child's body was found in the tank after it was drained. The tank had been checked the first night of the search, when people were looking for "a happy, smiley little boy," not a body, Meehan said.

"We did not look in every little nook and cranny," the sheriff said.

The rectangular tank was full to within inches of the top, Meehan said.

The tank's lid was in place when the search began, he said, and that is why the tank was not drained immediately. The boy could have lifted the lid, Meehan said. Authorities have been investigating whether he could have put it back in place after entering the tank.

"I would be speculating, but I would say it is highly unlikely," Meehan said.

Loic's mother, Ariel Rogers, has confirmed she and her husband are divorcing and had been battling for custody of their three children. Mark Rogers received temporary custody during the couple's separation.