The X Factor judge has turned to her former boyfriend to produce the new track after previous cut 'Live It Up' failed to crack the UK Top 10.
"I just found out Tulisa is releasing a double A-side for her next single and one of the tracks is called 'Freedom', which I wrote and produced, so it's cool I'm still contributing to her success," Fazer told the Daily Star.
Contostavlos recently told Digital Spy that upcoming ballad 'Sight of You' will "stand the test of time", adding: "I hope it touches people."
The star's debut solo album The Female Boss will be released in the UK on November 26.
Contostavlos has worked with The-Dream (Rihanna), Rico Love (Usher), Toby Gad (Kelly Clarkson), Jean Baptiste (Black Eyed Peas) and Diane Warren (Mariah Carey) for the project.
Watch the music video for Tulisa's 'Live It Up' below: