Whitney Houston's ex-husband is 'struggling'

Whitney Houston's ex-husband Bobby Brown is said to be struggling following the news that the iconic singer has died.

Houston was found dead in a hotel room at the Beverly Hilton hotel in Los Angeles on Saturday afternoon (local time). She was 48.

A CNN reporter has spoken to singer Johnny Gill who is in Memphis with Brown, as their group New Edition is currently on tour.

"Bobby is struggling and he's devastated," Johnny told the news channel.

Brown reportedly went on stage hours after finding out about the death of his former diva wife and said: "First of all, I want to tell you that I love you all. Second, I would like to say, I love you Whitney. The hardest thing for me to do is to come on this stage."

Gill said that Brown had spoken to his 18-year-old daughter, Bobbi Kristina, and said she was not doing well.

Brown and Houston divorced in 2007 after 15 years of marriage.

There had been reports that her on-again, off-again boyfriend, singer Ray J, had found her dead, but her publicist has denied this and says it was her bodyguard who found her.

Celebrities have taken to Twitter in their droves to voice their shock and sadness at the passing of one of America's greatest talents.

"Heartbroken and in tears over the shocking death of my friend, the incomparable Ms. Whitney Houston," Mariah Carey wrote.

"She will never be forgotten as one of the greatest voices to ever grace the earth."

"No words! Just tears," Rihanna wrote. "Feels so strange being at the Grammy rehearsal right now!"

"So devastating. We will always love you Whitney, R.I.P," Katy Perry posted.

"Just heard the news. So crazy," Justin Bieber tweeted. "One of the GREATEST VOICES EVER just passed. RIP Whitney Houston. My prayers go out to her friends and family I am sadden to hear of the passing of Whitney Houston today." (sic)

Houston's death comes just a day before the biggest event in the music industry - the Grammy Awards - and organisers are said to now be scrambling to put together a suitable tribute to the star.

- AAP/AP