'Britney Spears claimed she was lied to and silenced by her team during the height of her troubles, which saw her children taken away and the 26-year-old star put on a psychiatric hold, in a never-before-seen letter obtained exclusively by DailyMail.com.
Spears, who writes the letter in the third person, claims she was 'set-up' when she was placed on psychiatric hold after locking herself into a room and refusing to hand over one of her two sons to her ex-husband Kevin Federline in January 2008.
She accuses her team of 'controlling her life' and 'constantly threatening' that her children would be taken away if she didn't cooperate with them.
The handwritten note was given to a member of Spears' camp between 2009 and 2010 and uncovered by DailyMail.com.
The unearthed letter comes as fresh concerns have arisen about Spears' well-being after she claimed her father committed her to a mental health facility in April and forced her to take medication against her will.
The insider told DailyMail.com that Spears wrote the letter to clarify the circumstances surrounding her psychiatric hold in 2008 and to give her side of the story.
They said: 'I think she was frustrated with what was going on and what was being reported and said.
'She didn't usually get a chance to speak her mind and be heard. She is thoughtful and sweet.'
Spears starts the letter, which is written in the third person, by taking a shot at ex-husband Federline and the breakdown of their marriage in 2006.
She writes: 'After reading Kevin's article in People I was amazed at how a lot of the focus was on Britney their mother to sell a story for People magazine, instead of the focus being on Kevin.
'What happened to Britney was a year ago and people need to get with the times.
'And as far as Kevin saying Britney divorced him, she was forced to by her lawyers b/c she went to visit him in N.Y and he wouldn't see her and the children and her lawyers said if she doesn't divorce him he's going to do it himself.'
Read more: 'I was lied to and set up.' Britney Spears writes in never-before-seen letter how she was silenced and threatened by her team at the height of her troubles which saw her put on psychiatric hold and her sons taken away