The former judge responded to an Instagram post by Misha, who described how producers forced an “angry black girl” narrative on her during the eighth series in 2011.
The 28-year-old said the experience left her with suicidal thoughts, and that she was diagnosed with PTSD after the show.
“They saw an opportunity to tear down a black girl that came from a broken home and worked together to assassinate my character and to sabotage my career by orchestrating lies,” she said.
She added: “I know that I’m not the only one who has heard those words – feisty, mean… These are common words people use to describe black women.”
Contostavlos, who was mentoring eventual winners Little Mix, told Misha during the competition: “You being so feisty can come across quite mean.”
After initially responding to Misha’s video last week, the former judge released a full statement on the matter.
In a lengthy Instagram post, Contostavlos explained: “It’s been hard to find the words or know whether to speak at all, but I don’t want to leave things on the note of my last post.
“I can see clearly that a black female was and is still hurt by my actions on The X Factor. That became overshadowed in my mind last week.”
The singer went on to explain that her initial response was less about Misha and more of an emotional reaction to the abuse she was receiving as a result of the allegations.
“It was more of a reaction to online violent/ death threats to me & my family & people telling me to kill myself,” Contostavlos wrote.
After admitting that she “jumped to defense mode”, Contostavlos explained that she sent Misha a separate apology message.
A post shared by Tulisa Contostavlos (@tulisasinstagram) on Jun 23, 2020 at 1:13pm PDT
She continued: “I fully acknowledge the pain I caused and fully accept people should be angry about it. I can state again there was nothing racial in my thought process.
“When I referred to Misha as being feisty and competitive that was a reflection of myself because I saw myself in Misha.
“We are both very strong women and when I communicate with people I always jump to what I have in common to find a basis to connect.”
While she insisted that there was no racism behind what she said, Contostavlos apologised to Misha for how her comments might have “made her feel a certain way”.
“However, I totally understand that it made Misha feel a certain way”, she began. “As a young black girl hearing it from a young white girl on a huge platform, living in the oppressed society we do, full of racial slurs and undertones, not knowing my thought process.”
Looking back in hindsight, Contostavlos added: “I let my emotions get in the way of my work & I didn’t stop to think of the consequences for you, Misha, at the age of 18, immediate or long term.”