Stephen Belafonte has accused Mel B of abusing cocaine and alcohol.
In new court documents, submitted as part of their bitter divorce and custody battle and obtained by DailyMail.com, the producer accused his estranged wife of excessive use of the drug and alcohol and he claimed it left him worried about the safety of their daughter Madison, six and Mel's other children Angel, nine and Phoenix Chi, 18.
Stephen - who has filed for step-parent visitation of Angels, whose father is actor Eddie Murphy - said in his court filing: "The biggest reason for my concern with respect to the safety of the children was due to the Petitioner's habitual and consistent addiction to and abuse of cocaine and alcohol.
"To make matters worse, my fear for the children's safety was amplified due to the fact that Petitioner had fired the children's nanny, who had been in the children's lives since 2010 and I did not want Petitioner using drugs and drinking around the children especially without anyone else present to care for the children.
"Petitioner's drinking and drug abuse had been a major issue throughout our marriage and was witnessed by the nanny, the children, and her own therapist, Dr Sophy."
Mel, 42, fired nanny Lorraine Gilles after claiming she had been sleeping with Stephen behind her back but the former employee hit back and alleged that she had been sexually intimate with Mel and enjoyed threesomes with the star and Stephen.
Stephen also submitted text messages to the court, allegedly between him and Dr Charles Sophy, where the medical professional outlined the steps he and Mel were taking to deal with her alleged abuse of alcohol and drugs.
Stephen added in the documents, filed at LA Superior Court: "During the text exchange, in order to try to ease my concerns, Dr. Sophy, a mandated reporter, informed me that he would try to control Petitioner's alcohol and drug abuse and that he and Petitioner made an agreement regarding Petitioner's 'substance abuse', as well as 'child safety'."