Musicians Keith Richards (L), Paul Shaffer (C) and Peter Buck perform during the 22nd annual Rock and Roll Hall of Fame induction ceremony at the Waldorf Astoria Hotel in New York March 12, 2007. [Reuters]

The 91-year-old mother of Rolling Stones guitarist Keith Richards has died in Britain, a spokeswoman for the band said on Monday.

Doris Richards died on Saturday. The cause of death and the location were not disclosed.

Her son had kept a vigil at her bedside, forcing him to skip a memorial for the late record mogul Ahmet Ertegun last week.

Earlier this month, Keith Richards made worldwide headlines when he told a newspaper that he snorted the ashes of his father, Bert, after he died in 2002. He quickly retracted the comment, saying the story was "lost in the usual slanting."

Richards is the only child of Doris and Bert Richards, who split up in 1962. She bought her son his first guitar for his 15th birthday. He learned some chords from her father, Gus Dupree, a musician who instilled him with an early passion for music.

In her later years, she raised her granddaughter Angela. She is also survived by three other grandchildren, and two great-grandchildren.