Aspiring rapper Kevin Federline, who is currently separated from his wife, pop star Britney Spears, watches an NBA basketball game between the Atlanta Hawks and Miami Heat in Atlanta, Georgia, November 18. - Reuters

Kevin Federline is set to write a revealing book about his estranged wife Britney Spears.

The wannabe rapper, who split from Britney last month, is reportedly prepared to talk about the singer's alleged drug use, wild partying and her lesbian tendencies if he doesn't get what he wants from the divorce settlement.

A source told America's Star magazine: "Kevin is either hoping a publisher will pay him big money for the book, or that Britney will cough up more cash than what is in their prenuptial agreement to keep him from spilling the beans."

It has been reported that the prenuptial agreement entitles Kevin to US$360,000 in spousal support and US$7 million from the sale of their Malibu marital home.

Kevin has applied for sole custody of the couple's two children - 15-month-old Sean Preston and three-month-old Jayden James - and is reportedly seeking a settlement of at least US$20 million.

- Bangshowbiz