Grammy winner Kelly Clarkson has hit out at music legend Clive Davis for 'spreading false information' about her in his new tell-all memoir.

The 30-year-old star wrote a damming open letter today after the record executive claimed that she broke into 'hysterical sobbing' when he demanded that her smash hit 'Since U Been Gone' be included on her album, Breakaway.

Kelly - whose stellar career was guided by Davis after she won American Idol - lashed out, saying: 'I refuse to be bullied and I just have to clear up his memory lapses and misinformation for myself and for my fans. It feels like a violation. Growing up is awesome because you learn you don't have to cower to anyone - even Clive Davis.'

In what is turning into a war of  words between the pair the 80-year-old took to Twitter to defend his  book, writing: 'I am truly very sorry that she has decided to take issue with what I know to be an accurate depiction of our time together.'

Clive said. “Before the book was  published, I had every fact checked with five independent individuals  who were present on a daily basis throughout it all.'

In his book, The Soundtrack of my Life, the 80-year-old music executive - who discovered Whitney Houston - tells how he fell out with Kelly over her desire to help pen her own songs on her third album, My December.