Nick Gordon gave Bobbi Kristina Brown a “toxic cocktail” before putting her face down in a bathtub filled with cold water, according to an amended lawsuit.
Bobbi Kristina, the 22-year-old daughter of Whitney Houston, was found unconscious in the tub in January and placed in a medically-induced coma. She passed away last month.
A lawsuit alleging assault, battery and theft was filed against Gordon on June 24 and the amendment, which was filed on Friday, adds a wrongful death count.
It claims that after Gordon returned from a “cocaine and drinking binge” on January 31, the couple started arguing loudly in the kitchen of her Roswell, Georgia home before they moved upstairs.
During the 30-minute argument, Gordon allegedly accused Bobbi Kristina of cheating on him before "everything abruptly became quiet."
Gordon gave Bobbi Kristina a toxic cocktail that rendered her unconscious, according to the lawsuit.
He then put her face down in the bath tub so that she suffered brain damage, according to the amendment seen by INSIDE EDITION.
Gordon then allegedly left the bedroom wearing different clothes, got into bed, laid his head on a female guest's ankle and told her: "Now I want a pretty little white girl like you."
Around 15 minutes later, a guest went to check on Bobbi Kristina and found her face down in the tub with a swollen mouth and tooth hanging from her mouth, the lawsuit says.
Gordon then allegedly entered the room and ordered the room to be cleaned. Others then tried to resuscitate Bobbi Kristina.
She was rushed to hospital and later placed in a medically-induced coma. She ultimately passed away in hospice care on July 26.
The original lawsuit accused Gordon of assault, battery, intentional infliction of emotional distress, and transferring thousands of dollars from Bobbi Kristina’s account to his own without authorization.
As well as the addition of the wrongful death count, the amendment to the lawsuit provides further details about their allegedly abusive relationship.
It claims that days before she was found unconscious, Gordon punched Bobbi Kristina so that the couch she was sitting on broke.
She was allegedly knocked to the floor where Gordon allegedly continued to beat her "until she was bloody," according to the suit. Brown was screaming through the attack and lost a tooth, the lawsuit says.
Gordon then allegedly dragged her upstairs by her hair - leaving blood on the walls - as he told witnesses: "I don't do this often."
The lawsuit also describes him as controlling. It alleged he limited whom she interacted with and would not allow her to make appointments without his approval.
No criminal charges have been filed against Gordon. He has previously denied any wrongdoing.
He was taken in by Whitney Houston as a child. After her death in 2012, he began a relationship with Bobbi Kristina and said they were married - a claim her family has denied.
Following her death, Gordon had a public meltdown on Dr Phil and checked into rehab. He checked out in April and is reportedly staying with his mother.
Watch Below: Bobbi Kristina Brown Laid to Rest Next to Whitney Houston