The Slits' Ari Up has passed away aged 48. According to a statement on step-father John Lydon's website , the singer died yesterday (October 20) and had been suffering from a "serious illness".

Ari Up - real name Ariane Forster - formed The Slits at the age of just 14 in 1976, and the band released their debut album Cuts in 1979. Their next LP Return Of The Giant Slits followed in 1981 before the band went their separate ways. The band reformed in 2005.

News of Forster's death was confirmed by John Lydon - who is married to her mother - on his website. A statement said: "John and Nora have asked us to let everyone know that Nora's daughter Arianna (aka Ari-Up) died today (Wednesday, October 20th) after a serious illness. She will be sadly missed.

"Everyone at JohnLydon.com and PiLofficial.Com would like to pass on their heartfelt condolences to John, Nora and family.

"Rest in Peace."

Friend of The Quietus Everett True, meanwhile, also wrote the following message on his website Collapse Board: "Fuck. I don’t know what to write. This lady has been such a major influence on my entire adult life. She was younger than me. Ariane Forster, aka Ari Up, died yesterday, after a serious illness. The news was announced via John Lydon’s website a few minutes ago. I’ll miss her. Right up to her final single, she was vital.

"Ariane Forster was born January 1, 1962, and died October 20, 2010."

You can read a selection of Everett's writings about Ari Up and The Slits on Collapse Board now.

The Quietus would like to join everyone else in expressing our condolences to Forster's family, who our thoughts are with at this time.