Singer and DJ Sonique is suffering from breast cancer, her spokesman said today.
The performer, whose real name is Sonia Clarke, is having an operation at a clinic in Harley Street, central London.
She was told that she had the disease last Tuesday and is undergoing treatment as a matter of urgency, spokesman Stuart Watts said.
The singer, who enjoyed chart success with hits including I Put A Spell On You and It Feels So Good, was admitted to hospital at 7am today and is due to remain there until at least Saturday.
Clarke, 40, a Brit and Ivor Novello award-winner, is also a DJ and was resident at the Manumission nightclub in Ibiza from 1997 to 1999.
Mr Watts said she had a new single "World of Change" due for release in July, but whether this would go ahead depended on her health.
The singer, from Crouch End, north London, originally dreamed of becoming an athlete but then decided to concentrate on music.
She struggled to forge her fledgling career and was homeless for a period as a teenager, which she said "made me realise life wasn't a joke".
Fellow singers Kylie Minogue and Anastacia have also battled breast cancer in recent years.