Britney Spears is set to sign a 10 million book deal.

The 'Womanizer' singer is expected to begin writing her tell-all tome when she finishes her sell-out world tour 'The Circus Starring: Britney Spears'.

It is believed she could pen up to five explosive books over the next 10 years.

A source told Britain's Daily Mirror newspaper: 'There have been numerous unofficial biographies printed about Britney, but she's never agreed to pen her own tome - until now.

"And some of the stories she's got are absolute dynamite. She's kept diaries so there's nothing she'll leave out unless she wants to.

"If the deal goes ahead she will write between three and five books throughout the next decade - it's one of the most lucrative book deals in showbiz history.

"Britney will talk frankly about growing up and how she went off the rails. It'll be a gripping read."

Last year, Britney's mother Lynne left the star devastated when she released her revealing book 'Through the Storm: A Real Story of Fame and Family in a Tabloid World'.

It revealed how Britney – now 27 - started drinking aged 13, lost her virginity to at the age of 14 and took drugs when she was 15.