'Wrongful Death!' Nick Gordon Gave Bobbi Kristina Brown 'Toxic Cocktail' & Put Her Facedown In Tub, Causing Brain Damage -- Explosive Lawsuit Claims

Less than one week after Bobbi Kristina Brown was laid to rest, her estate has amended a lawsuit filed against her former boyfriend, Nick Gordon, with shocking new claims he gave her a "toxic cocktail" and placed her facedown in the tub where her lifeless body was found.

According to the amended suit, filed August 7, Gordon returned to the home he shared with Brown at 6 am on January 31 after "being all night on a cocaine and drinking binge," NBC News 11 Alive Atlanta reports.

The updated lawsuit reportedly claims the couple began arguing in the kitchen before moving upstairs to the master bedroom, where Gordon allegedly accused Brown of cheating in a heated fight that lasted roughly 30 minutes.

Soon, the lawsuit claims, "everything abruptly became quiet" and Gordon "gave Bobbi Kristina a toxic cocktail rendering her unconscious and then put her face down into a tub of cold water causing her to suffer brain damage."

Gordon then reportedly came out of the bedroom in a new set of clothes, the lawsuit alleges, and told a female guest, "Now I want a pretty little white girl like you."

The lawsuit claims that 15 minutes later, another guest found Brown in the tub unconscious and with a tooth dislodged from her gums.

The guest was soon joined by Gordon who allegedly began shouting "Clean up, clean up," and attempted to revive her.

The lawsuit claims she was later diagnosed with "irreversible brain damage" that was allegedly "as a result of Gordon's actions.

As RadarOnline.com reported, Brown's conservators filed the $10million lawsuit in Fulton County Superior Court on June 24, accusing Gordon of assault, battery, intentional infliction of emotional distress, and transferring money from her account into his own without authorization -- claims Gordon denied across the board.