Divers are focusing on a specific stretch of the Connecticut River in the search for Celina Cass, an 11-year old New Hampshire girl who has been missing for a week.

Local New Hampshire news station WMUR reported that a search crew had zoned in on a section of the river near the Canaan Hydro-Dam on Monday. At approximately 10: 45 am, New Hampshire Assistant Attorney General Jane Young and other investigators arrived at the scene, and media were asked to leave the area.

Earlier this 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 has offered a $25,000 reward for anyone who provides information that leads to Celina's whereabouts or an arrest in her disappearance. A private citizen has offered an additional $5,000 reward.

"We are still aggressively, aggressively searching and hoping to bring Celina Cass home," FBI Supervisory Special Agent Kieran Ramsay said in a news conference on Saturday.

Authorities have increasingly intensified efforts to locate Celina since her disappearance, and residents of West Stewartstown -- which has a population of about 800 -- have 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.

Celina's mother and stepfather have not made a statement since their daughter disappeared.

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 would not 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."

Celina is 5-foot-5 and weighs 95 pounds, with long brown hair and hazel eyes and was last seen wearing a pink shirt, a pink pullover, blue shorts and shoes.

Any information about Celina Cass' whereabouts should be directed to New Hampshire State Police at 603-846-3333.