He claimed that Belafonte had been incredibly "controlling" as well as "aggressive and verbally abusive," often deeming Mel and the children "ugly" or "disgusting".
He added that he was also Mel's confidant during the troubling time, and she would often tell him about how she attained the bruises while remaining tight-lipped with other members of her team.
However the make-up artist went on to allege that he was sworn to secrecy by Belafonte about the damaging information - with the film producer issuing a number of threats or refusing to pay him if he spoke on the matter.
Yet, he is now reportedly set to take his claims to a legal level in order to help Mel in her battle for sole custody over the couple's daughter Madison, 5.
Belfonte previously called allegations of domestic abuse "outrageous" and "unfounded."
Meanwhile Mel B has reportedly made a huge change to her petition to divorce Belafonte, asking that she get permanent sole custody of their five-year-old daughter Madison, having previously asked for joint custody.
According to TMZ, the former Spice Girl, 41, has done a complete U-turn after learning that Belafonte's previous domestic violence conviction towards another woman means that he is prohibited from owning a gun.
The site claims: "Mel knew Stephen had a gun and was not happy about it, especially since she alleges he repeatedly committed domestic violence against her.
"But we're told after recently finding out the gun was illegal to possess, she decided to change her custody strategy."
TMZ also reports that Mel is now planning to make her temporary restraining order permanent after claiming Belafonte used "racial slurs against her, got the nanny pregnant and was violent towards her in front of the children."
Moreover, they claim that while Mel might allow monitored visits with Madison in the future, she doesn't want Belafonte having contact with her other children.
She has Angel, 10, from her romance with Eddie Murphy and Phoenix, 18, from her previous marriage to Jimmy Gulzar.
Belafonte, 41, has asked for joint legal and physical custody of Madison and is asking for spousal support, the documents show, although no figure is stated.
The filing also reveals the former couple disagree on their separation date - him claiming it was March 1 and she December 28.
Mel was spotted leaving her lawyer's office for a second day in a row on Thursday as she prepares to take on a messy divorce battle with Belafonte.
Mel states in the documents: "I am in fear for my safety and that of my children... Likewise the Respondent's emotional and physical abuse of Petitioner in the presence of the minor child is tantamount to abuse of the minor child."
She continues: "I have tried to leave the Respondent many times. Every time I tried, the Respondent threatened me with violence and threatened to destroy my life in every way.
"He said he would destroy my career and take my kids from me. He threatened to release sexually explicit videotapes claiming I would never again work in the entertainment industry."
