Police say no visible drugs at Bobbi Kristina Brown's house, details remain short

Whitney Houston's daughter, Bobbi Kristina Brown, remains in critical condition, multiple sources confirm.

Very few details have emerged since Bobbi Kristina, 21, was found unconscious in the bathtub of her Roswell, Georgia, home on Saturday, Jan. 31, but the Roswell Police Department recently revealed that they are conducting a very thorough investigation.

"We don't leave any stone unturned," Roswell Police Department's Lisa Holland told UsWeekly. "So the police took a search warrant on the home. Before the warrant, initially when the police went into the home there were nothing there that indicated that anything out of the ordinary happened. There were no drugs out in the open."

Holland declined to comment on the condition of Bobbi Kristina at the time of the interview.

"I can't comment on her condition because of medical privacy laws," Holland told UsWeekly. "I know she is alive and the only thing they would notify me of is if her condition changed."

Sources are reporting that Bobbi Kristina's condition remains serious and she is still at North Fulton Hospital in a medically induced coma.

EARLIER: Bobbi Kristina Brown reportedly in 'bad shape'

Earlier this weekend, her father, Bobby Brown, asked for privacy for the family at this difficult time.

"Privacy is requested in this matter. Please allow for my family to deal with this matter and give my daughter the love and support she needs at this time," Brown said.

Close family friends have also taken to social media to send their well-wishes and prayers to Bobbi Kristina.

Super Bowl performer Missy Elliott posted a tweet late Saturday and later posted a follow-up tweet on Sunday.

SEE MORE: Celebrities offer support for Whitney Houston's daughter

It has been nearly three years since Whitney Houston died of an accidental drowning on Feb. 11, 2012, at The Beverly Hilton.