Jennifer Hudson hasn't "stopped crying" since Whitney Houston's death.

The 30-year-old star was honoured to be picked to pay tribute to Whitney at the Grammy Awards on Sunday (12.02.12), and performed a version of 'I Will Always Love You' the day after she was found dead in her room at the Beverly Hilton hotel.

Jennifer has found it hard to contain her emotions since learning of her idol's death.

She told Us Weekly magazine: "It was the greatest honour of my life to be able to be the one to pay tribute to Whitney's memory."

Speaking of her performance, she added: "It was from my heart. I haven't stopped crying since she passed. Her family is in my prayers."

The Grammy awards included a video montage of the stars who had died over the last year - including Amy Winehouse, Etta James and rapper Heavy D - and finished with a freeze frame of Whitney, after which Jennifer appeared on stage in a svelte black dress. She was visibly emotional as she gave a note perfect rendition of the track, and as she finished she broke down in tears.

The cause of Whitney's death has not yet been released, and her autopsy details are being kept under wraps until toxicology reports have been completed.

However, it is believed her death was caused by a lethal combination of prescription drugs and alcohol.

Many other stars have paid tribute to the singer including former Destiny's Child star Kelly Rowland.

Kelly said: "We lost our hero. I would not be standing here today if it was not for her.

"My prayers go to her mother and her daughter. If we feel this loss I can only imagine how heavy their loss is."

British singer Alexandra Burke tweeted: "I'm still so cut up about Whitney. To the point where I can't sleep ... Losing her has hit me hard ... I wish it wasn't real. (sic)"