The original lawsuit filed on June 24 by Brown's court-appointed conservator, Bedelia Hargrove, claimed that Gordon assaulted Brown and stole thousands of dollars from her.
The amendment adds a wrongful death accusation, claiming that after a late-night "cocaine and drinking binge" Gordon "gave Bobbi Kristina a toxic cocktail rendering her unconscious and then put her face down in a tub of cold water causing her to suffer brain damage."
Gordon entered rehab following his public meltdown while shooting an interview on The Dr. Phil Show on March 6, and checked out of rehab in late April. He was since spotted in Florida, and made an emotional plea to attend Brown's funeral in Atlanta last weekend. He has reportedly been back home with his mother, Michelle Gordon.
No criminal charges have been filed against Gordon to date.
Days before she was found unconscious in a bathtub in her townhouse, a bloody fight broke out between Gordon and Brown, according to the filing. Gordon "lunged onto Bobbie Kristina while she sat on the living room couch, hitting her so hard in the face that the couch broke, knocking her to the floor, and continued to beat her in the face until she was bloody. Afterwards, he began kicking Bobbi Kristina in the side to the point that she was on the floor screaming and curled up in the fetal position."
Allegedly, "Bobbi Kristina's tooth was knocked out and blood was on the floor" after this fight.
The filing goes on to claim that Gordon then "dragged her upstairs by her hair and threw her in the master bedroom." Afterward, he allegedly told those present, "I don't do this often."
According to the original filing, Brown set up a meeting with someone where she was expected to tell this person that Gordon "was not the man she thought she was." However, she never made it to that meeting.
At around 6 a.m. on Jan. 31, when Gordon allegedly returned home after "being out all-night on a cocaine and drinking binge," the two had a heated argument. Gordon allegedly accused Brown of cheating, calling her a "whore" and a "b***h."
"The argument lasted for about thirty minutes and then everything abruptly became quiet," the filing claims. It is during that time period that the filing alleges Gordon gave Brown a "toxic cocktail" and "put her face down in a tub of cold water."
"Gordon then came out of the master bedroom wearing a different set of clothing than he was wearing prior to his argument with [Brown]," the filing claims. "Afterward he got in bed, and laid his head on [his] female guest's ankle and stated, 'Now I want a pretty little white girl like you.'"
About 15 minutes later, according to the suit, another person at the townhouse found Brown in the tub. "A dust pan was in the bottom of the bathtub," the filing notes, adding that "Bobbi Kristina was unresponsive, unconscious, her mouth was swollen, and another tooth was hanging loosely from her mouth." Gordon and the other person present, the lawsuit says, performed CPR, with Gordon also slapping her face and saying, "Wake up."
A source close to the investigation tells ET Roswell PD has sent their records over to the Fulton county DA's office for review. They will look closely at all of the information that was compiled during the investigation when she was discovered in the bathtub. Additionally, it is believed that any possible injuries Bobbi Kristina may have sustained in the car accident she was in just days before she was found unresponsive will be crucial to the case. However, the DA has no update at the time.
UPDATE: Nick Gordon's lawyers released a statement Saturday morning regarding the lawsuit filed against their client, claiming it is both "slanderous and meritless."
"Nick has been heartbroken and destroyed over the loss of his love and it's shameful that such baseless allegations have been presented publicly," the statement reads. "Nick has engaged civil counsel and intends to defend the lawsuit vigorously and expose it for what it is: a fictitious assault against the person who loved Krissy most."
ET has reached out to Brown's conservator for comment, as well as her father, Bobby Brown.