Whitney Houston's family are "glad to now have closure" on her death.

The music icon passed away at the age of 48 in a bathtub at a Beverly Hills hotel room last month.

Authorities revealed Thursday that Whitney officially died of drowning, but a sustained use of cocaine also contributed to her death.

TMZ reports that enough cocaine was found in Whitney's blood to indicate that she used the narcotic "immediately prior to her collapse."

Whitney's family are dispirited by the knowledge that the singer relapsed into drug use, as they thought she was clean before her demise.

"We are saddened to learn of the toxicology results, although we are glad to now have closure," the family released in a statement.

Although toxicology results indicate that Whitney used the drug moments before she died, no trace of cocaine was found in the hotel room by authorities.

A source told TMZ that the person who supplied her with the dope was the person who cleaned up the scene.

The Beverly Hills Police Department initially suspected no foul play, but the investigation remains open.

Law enforcement will not comment on whether or not they are investigating allegations of foul play.