Heidi Montag is writing an autobiography.

The onetime 'Hills' star - who recently announced she and her husband Spencer Pratt are broke - is set to pen her memoirs and reveal shocking details about her marriage to her former co-star and why her Friendship with Lauren Conrad fell apart.

A source said: "She'll talk about the control that Spencer exerted over her, which forced her to make bad decisions that ultimately got her kicked off 'The Hills'.

"A big chunk of the book will be about how Heidi befriended Lauren and how devastated she was when she ended up dumping her as her BFF. Maybe something positive will come out of it

"She's happy to have people read the full story and make up their own minds."

Heidi is also set to spill the beans on her dramatic plastic surgery which saw her transform her looks with 10 operations in one day.

The source added to National Enquirer magazine: "She blames a lot of it on the pressure of being in the public spotlight. She wanted to make herself look like a Barbie doll."