The Australian rapper, 31, told People she broke her silence because she would have wanted other artists to support her if she were in the same position.
'I know her and love her. She's such an icon and inspiration and was so kind to me that if I could help her in any way that I can, then I want to do that,' she said.
'I know her and love her': Iggy Azalea (left) stands by her decision to publicly support Britney Spears (right) as the pop star attempts to terminate the 13-year conservatorship helmed by her father, Jamie. Pictured together on May 17, 2015, in Las VegasInsurance Loans Mortgage Attorney Credit Lawyer
Iggy, who collaborated with Britney on the track Pretty Girls in 2015, said she'd previously kept quiet to respect her friend's 'privacy'.
But after watching the Toxic singer's public court hearing on June 23, in which she begged to be released from her conservatorship, she couldn't stay silent any longer.
'I just thought if I were in her shoes, I would want my friends to back me up. I felt like, you know what? Regardless of what people might think about it, I have to say something,' she said.
Iggy claimed last week she'd 'personally witnessed' Britney's father Jamie control her life while they worked together in 2015, and also alleged he'd forced her to sign an NDA to perform with Britney.
'I were in her shoes, I would want my friends to back me up': The rapper, 31, broke her silence because she would have wanted other artists to support her if she were in the same position
The Fancy rapper supported the Britney's claims she was in an 'abusive' situation, taking to Twitter to tell fans she was 'not exaggerating or lying' about her father's treatment while posting under the #FreeBritney hashtag.
'Its basic human decency to at the very least remove a person Britney has identified as abusive from her life. This should be illegal,' Iggy wrote.
Talking about their work on the song Pretty Girls together, Iggy said: 'During the time we worked together in 2015, I personally witnessed the same behavior Britney detailed in regards to her father last week and I just want to back her up and tell the world