South African actress and singer Winnie Khumalo has died at the age of 51 after a short illness, her family has announced.

The Afropop singer was known for her long musical career which began in the 1980s, and also appeared in popular South African TV series.

She is best known for her hit song Live My Life and has collaborated with prominent South African artists including the late Brenda Fassie.

Her sister Tshepi Akeepile said the singer died on Tuesday on the way to the hospital.

"My sister was sick. She did have a short illness and we really thought she was recovering. But this morning it turned out she hadn't fully recovered from her illness. She was quickly rushed to the hospital. Unfortunately, she was pronounced dead," Ms Rakeepile told SABC TV.

It is not clear what she was suffering from.

Khumalo leaves a rich music and television legacy and was a household name for her powerful voice and versatile performances.

She released numerous solo albums, as well as being the back-up singer to Brenda Fassie.

She is survived by her daughter, Rethabile Khumalo, who is also a singer and her son, Thabo Khumalo.

Fans and fellow celebrities have taken to social media with tributes, expressing shock and sadness.

The Kalawa Jazmee Records, the record label that Khumalo worked with, described her as a "true icon" for inspiring many with her powerful voice and "unforgettable performances".

"Her passion, talent, and dedication to her craft have left an indelible mark on the industry and in the hearts of her fans," the label said in a statement.