Beverly Hills Police said in a written statement that they could not yet speculate on the cause of Houston's death.

"She was underwater and apparently unconscious," Beverly Hills police said in the statement. "Ms. Houston was pulled from the tub by members of her staff and hotel security was promptly notified."

The 48-year-old singer, who battled drug addiction during her life, was found dead in the bathtub of her Beverly Hills hotel room on Saturday on the eve of music's Grammy Awards.

Her death stunned family and fans, and prompted questions about what might have caused the death of the wealthy superstar.

Some reports, citing unnamed sources close to Beverly Hills police and Los Angeles County coroners, have cited a possible accidental drowning and others have highlighted her past drug use. Coroner's officials have declined to provide much detail pending toxicology tests that could take six to eight weeks to complete.

"As can be expected in a high profile incident such as this there have been many rumors circulating and much speculation by the media and the public," Beverly Hills Police said in the statement.

"In order to minimize such speculation, the Beverly Hills Police Department has asked the Coroner's office to place a security hold on their findings until they have a complete and final report prepared."

Police said in the statement that Houston's body was discovered in the tub at about 3:30 p.m. by a member of her personal staff.

Fire department personnel and hotel security arrived and initiated CPR but were unable to revive her, police said.

Earlier on Monday, officials said that Houston's body can be released to her family following the autopsy.

A spokeswoman for the late singer said plans for funeral and memorial services were not complete.

Houston's brother-in-law, Billy Watson, on Monday vehemently denied to ABCNews.com that the singer had any intention of committing suicide.

"Oh, no, this is accidental," Billy told ABCNews.com. "She wouldn't have left her daughter like that. She wouldn't have done that to her daughter," he said, referring to 18-year-old Bobbi Kristina Brown, who is said to be distraught over her mother's death.

Watson, whose sister is married to Houston's brother, Gary, said the family is flying back to New Jersey from California today and Tuesday.

Ed Winter, the assistant chief coroner for Los Angeles County, declined comment on media reports that Houston had not drowned, but likely died from a combination of alcohol and prescription drugs including anti-anxiety medications.

"You can look at a body and not know what the cause of death is," Winter told reporters.

"You might have a suspicion, but the person could have suffered a heart attack, or an embolism or something; and no matter what medications they're taking, until we run (toxicological tests) and see the level, and what's in the system, we're not going to speculate,"

Houston, best known for her hit single "I Will Always Love You," the theme song of "The Bodyguard" film in which she starred, had a long history of addiction to alcohol, cocaine and marijuana and had been in rehab as recently as May 2011.

She had been preparing to appear at a pre-Grammy party in Beverly Hills on the night she died.

(Additional reporting By Jill Serjeant; Editing by Bob Tourtellotte and Jackie Frank)

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