A decomposed body was found today just one mile from where 12-year-old Kayleah Wilson of Greeley, Colo., went missing nearly two months ago.
A source close to the investigation told ABC News' Denver affiliate 7News that they believe the body is Kayleah's but cannot be certain until dental records are compared.
Greeley Police Sgt. Joe Tymkowkych did not immediately return messages left by ABCNews.com, but told local reporters that the body was discovered at 6 a.m. Wednesday by a worker who was inspecting the water levels in an irrigation ditch.
The body is so decomposed that is was not immediately clear if it was that of a female or a male, said Tymkowkych.
It is "impossible to tell right now when the body was deposited," Tymkowkych told 7News.
The search for Kayleah, who went missing March 28 after leaving her Greeley home to attend a birthday party, has been confounded by an absence of any information or leads, police have said.
Last month, the FBI doubled the amount of reward money they are offering from $10,000 to $20,000.
At the time, James Davis, special agent in charge of the Denver FBI office, said the FBI has cut back significantly on the staffing assigned to the case, although that could change if new leads or information surfaces.
Greeley Police Chief Jerry Garner said in April that investigators remained motivated, but acknowledged that the chances of finding Kayleah safe decreased with time. While officials say they still can't rule out that Kayleah is a runaway, that possibility is becoming less likely.
"It's very unusual not to have any indication to point us in a direction one way or another," Garner said.
"We still can't rule out the fact that she ran away on her own, although I will say given the amount of time she's been gone and without any contact from her, we're definitely leaning in the direction that this is not a runaway situation and that this is something worse than that," said Davis.
Davis said there are no suspects in the case, and urged the public to pay attention to anyone who may be behaving strangely, such as someone having trouble sleeping or expressing an unusual interest in the case.
Community members have been active in the investigation, and under the direction of Bob Walcutt, executive director of The Laura Recovery Center for Missing Children, a Texas-based nonprofit organization called in by the girl's family to help, scoured Greeley for the teen.
"We're going to do whatever we can to find this young girl," Walcutt said.
Greeley police directed the search organizers to areas to look for any signs of Kayleah, Walcutt said.
"As it is at the moment, we don't have any clear direction where she went, or who she went with," Walcutt said. "Right now we are just eliminating areas where she is not."
Kayleah's mother, April Wilson, said that disappearing without calling or coming home is not typical of her daughter.
"She's never run away before," Wilson said. "I am worried she may be in danger because none of her friends have seen her, and it is like she just vanished, but that's not possible."
Kayleah, a sixth grader at Brentwood Middle School, was last seen wearing a white-and-pink shirt over a white tank top, blue jeans and white and red shoes. She is described as being 5 feet 1 inch, and approximately 145 pounds with brown eyes and brown hair.
Wilson said her daughter left at 3:40 p.m. for the party, which was just a few blocks away.