A female body has been found in the Connecticut River where police have been searching for evidence leading to the whereabouts of Celina Cass, an 11-year-old girl who has been missing since last Monday.

Essex County state attorney Vincent Illuzzi told WMUR, a New Hampshire-based CNN affiliate, that no identification had yet been made on the body.

Earlier on Monday, WMUR reported that a search crew had zoned in on a section of the river near the Canaan Hydro-Dam, which is close to the New Hampshire border in Vermont. At about 10:45 a.m., New Hampshire Assistant Attorney General Jane Young and other investigators arrived at the scene, and media were asked to leave the area.

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's biological father, Adam Laro, spoke out for the first time on Sunday, pleading for his daughter's safe return. Laro was reportedly in the hospital when Celina disappeared, but has since been released.

"Whenever you want to come home, Celina, Daddy will be here waiting for you," Laro is quoted as saying by CNN.

Celina Cass was last seen on the evening of July 25 in her West Stewartstown, N.H. home.

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.

In addition to the FBI, the Royal Canadian Mounted Police joined the search effort last week, and on Friday the Connecticut River was lowered to aid in a helicopter search for evidence of Celina's whereabouts

The home that Celina Cass shares with her mother, sister, and stepfather is a mile from the Canadian border.

Officials told ABC News on Thursday that the disappearance was still being treated as a missing persons case.

"Every house, every individual in the neighborhood is being spoken to," Young said.

Those who knew Celina believe the girl wouldn't have run away.

"She never went anywhere without her mom or sister," family friend Rebecca Goodrum told the Boston Herald during a candlelight vigil Wednesday night.

"She is very shy," added Kayla Baglio, 18, who also knew the girl. "If she doesn't know you, she'd look at her sister to see if it was OK to talk to you."