Miss Lee, 78, is best known for her rendition of Fever and in 1969 won a Grammy for best contemporary female vocal performance for the hit Is That All There Is?

Her daughter Nicki Lee Foster said: "She's conscious and her family has been with her."

Ms Foster said doctors were trying to determine whether the stroke, which the singer suffered on 27 October, had caused permanent damage.

A diabetic, Miss Lee has suffered a string of health problems including a near-fatal fall in a New York hotel in 1976.

She was seriously injured in a Las Vegas fall in 1987 and in early 1985, she had surgery to open clogged arteries. Later that year, she underwent double-bypass heart surgery.