Authorities have confirmed that a body found in the Connecticut River on Monday is 11-year old Celina Cass, who vanished from her New Hampshire home on July 25.

Investigators are treating the death as suspicious, New Hampshire news station WMUR reported.

The announcement comes hours after investigators reported finding an unidentified female body in the river, news that had those following Celina's story fearing the worst.

WMUR reported Monday that relatives of the girl were seen crying outside the West Stewartstown home Celina shared with her mother, sister, and stepfather.

Online commenters to an earlier WMUR story about the missing girl expressed concern that the unidentified body may turn out to be Celina, though some were holding out hope that the story might have a positive outcome.

Several comments call attention to the Facebook profile of Celina's stepfather, Wendell Noyes, referring to Noyes as a "creeper" and questioning whether the Cass family was aware of the profile.

The overwhelming majority of Noyes' Facebook "friends" are young women from different parts of the country, some appearing to be amateur models. The page -- which is available for the public to view -- shows that Noyes posted flirtatious comments on some of the girls' profiles as recently as June.

On Monday morning, Celina's stepfather was taken to the hospital via ambulance.

WMUR reported that Wendell Noyes was suffering from "some sort of medical problem" and was taken to Upper Connecticut Valley Hospital after being carried to an ambulance on a stretcher. No further details were given.

In 2003, Noyes was forcibly committed to a hospital with a diagnosis of schizophrenia, ABC News reported. ABC obtained court records showing that Noyes has an arrest record for violating a restraining order and threatening his ex-girlfriend.

Celina Cass was last seen on the evening of July 25 in her bedroom. WMUR reported that Celina's mother and stepfather told authorities the girl was gone when they went to wake her up the following morning.

The FBI joined the search the missing girl last week, offering a $25,000 reward for information leading to her whereabouts or an arrest in connection with her disappearance.

Authorities increasingly intensified efforts to locate Celina in the week following her disappearance, and residents of West Stewartstown -- which has a population of about 800 -- banded together to assist a frantic search for the schoolgirl, who is described as "shy" and unlikely to have run away.