Singer Houston died of drowning

Singer Whitney Houston died from drowning and heart disease, and signs of cocaine use were found, a coroner in Los Angeles has ruled

The announcement ends weeks of speculation about what killed the Grammy-winning singer on February 11.

Houston was found submerged in the bathtub of her room at the Beverly Hilton Hotel on the eve of the Grammy Awards.

Several bottles of prescription medications were found in her hotel room, but coroner's officials said they weren't in excessive quantities.

Coroner's spokesman Craig Harvey says cocaine metabolites were found in Houston's system, and it was listed as a contributing factor in her death. He says the results indicated Houston was a chronic cocaine user.

Houston died just hours before she was scheduled to appear at producer Clive Davis's pre-Grammy Awards bash.

She was buried in a New Jersey cemetery next to her father after an emotional four-hour funeral service that was attended by friends, family and superstars such as Oprah Winfrey, Tyler Perry, Alicia Keys, Mariah Carey, Mary J Blige, Jennifer Hudson and Roberta Flack.

Houston, a sensation from her first, eponymous album in 1985, was one of the world's best-selling artists from the mid-1980s to the late 1990s, turning out such hits as I Wanna Dance With Somebody, How Will I Know, The Greatest Love Of All and I Will Always Love You.

But as she struggled with drugs, her majestic voice became raspy, and she could no longer hit the high notes. Interest in her music has rocketed since her death, with her songs pushed back into the charts and frequently played by radio stations.

Patricia Houston, the singer's sister-in-law and manager, said: "We are saddened to learn of the toxicology results, although we are glad to now have closure."