Former American Idol contestant Nikki McKibbin has died in the US at the age of 42.

The singer, from Texas, appeared on the talent show's first season in 2002, finishing in third place behind Justin Guarini and winner Kelly Clarkson.

Her husband Craig Sadler said she had suffered a brain aneurysm last Wednesday and was taken off life support in the early hours of Sunday.

"I know thousands of you will be grieving with us," he said on Facebook.

"She loved so many of you and I know you loved her too."

In his post, Sadler wrote that his wife had been kept on life support because she was an organ donor.

"Even at the end she is still giving. There are only a few hours left for me to hold her hand and kiss her forehead," he said.

Writing on Instagram, Guarini paid tribute to his former competitor.

"[She] was a fiery, funny lady who could sing the hell out of a rock song with the same kind of ease and command she lovingly used to cut you with her twangy Southern wit," the singer said.

McKibbin won legions of fans during her time on American Idol, thanks to her striking, punky red hair and full-throated renditions of songs like Pat Benatar's Heartbreaker, Janis Joplin's Piece Of My Heart and Alanis Morissette's Mary Jane.

A longtime fan of Stevie Nicks, McKibbin covered her song Edge of Seventeen for one of her final American Idol performances.

The Fleetwood Mac star later sent her a bouquet of flowers and a card that read, "You are the Gypsy that I was," Guarini said on Instagram.

The gesture put her "on cloud nine and the joy and excitement that radiated from her was infectious," he wrote.

The singer's husband added that, shortly before McKibbin's life support was turned off, they played the Fleetwood Mac song Landslide for her "one last time".

Before American Idol, McKibbin appeared on the rival reality show Popstars. She got her big break after impressing judges Simon Cowell, Paula Abdul and Randy Jackson in Dallas - where she forgot the name of her audition song, Whitney Houston's One Moment In Time.

"Unlike a lot of other people we've seen, I would remember you," said Cowell after her performance.

After making the season finale, she was signed to Sony Music's RCA label and released her first record, Unleashed, in 2007.
'Eases the pain'

She later struggled with alcohol and substance abuse - a battle that was chronicled on the TV show Celebrity Rehab With Dr. Drew in 2008, and a subsequent spin-off, Sober House.

In 2014, she returned to the show accompanying her then 15-year-old son, Tristan Langley, as he auditioned for judges Harry Connick Jr, Keith Urban and Jennifer Lopez. He passed the audition but was cut during the Hollywood rounds.

"Nikki McKibbin was an incredible talent and we are deeply saddened by the news of her passing," a spokeswoman for the contest said in a statement.

"She was part of our American Idol family and will be truly missed. Our hearts and prayers go out to her family and friends during this difficult time."

Updating his Facebook page after news of McKibbin's death broke, Sadler thanked fans for their messages and support.

"It eases the pain to be reminded how loved she was," he wrote. "I believe that Nikki can feel your love."