Nick Gordon is being accused of causing the "wrongful death" of girlfriend Bobbi Kristina Brown by giving her a "toxic cocktail," presumably of drugs and alcohol.

In an amended complaint, initially filed by the conservator of Brown's estate in late June, the 25-year-old Gordon is also accused of physically abusing Whitney Houston and Bobby Brown's 22-year-old daughter and stealing money from her.

"Consistent with and to the letter of the civil action I initially filed on behalf of Bobbi Kristina, we will continue to pursue justice for her," conservator Bedelia C. Hargrove said in a statement released to People magazine. "I have filed today an amended complaint against Nicholas Gordon adding a count for wrongful death and for pain and suffering. We will leave no stone unturned in seeking justice for Bobbi Kristina Brown."

Gordon's attorneys Jose Baez and Joe Habachy quickly dismissed the suit as "slanderous and meritless," adding that Gordon is heartbroken and destroyed over the loss of his longtime love.

Specifically, the complaint alleges that Gordon arrived at the Roswell townhouse he and Bobbi Kristina shared around 6 a.m. Jan. 31, after "being out all-night on a cocaine and drinking binge."

The suit alleges that, after reviewing camera footage and listening to her conversations, Gordon began to argue with Bobbi Kristina loudly, accusing her of cheating and calling her such names as a "wh*re" and a "b*tch." After about 30 minutes, everything allegedly became quiet.

By then, Hargrove contends Gordon had given Bobbi Kristina the "toxic cocktail" that rendered her unconscious. It's alleged that he then proceeded to put her face down in a bathtub of cold water and eventually came out of the master bedroom wearing different clothes.

Another woman was allegedly at the home at the time and, after leaving the master bedroom, Gordon is reported to have "laid his head on female guest's ankle and stated, 'Now I want a pretty little white girl like you.'"

Minutes later, another guest allegedly went to check on Bobbi Kristina and found her "unresponsive, unconscious" with a swollen mouth and "another tooth hanging loosely from her mouth," according to documents.

The complaint further alleges that Gordon then quickly returned to the master bedroom, let the water out of the bathtub and shouted "Clean up, clean up," while others began mouth to mouth resuscitation.

Bobbi Kristina and Gordon allegedly got into a fight just prior to what proved to be the deadly incident, during which Gordon "lunged onto Bobbi Kristina while she sat on the living room couch ... and continued to beat her in the face until she was bloody."

The only daughter born to Whitney Houston and Bobby Brown died on July 26 under hospice care. She never regained consciousness upon being rushed to a hospital emergency room on Jan. 31. She has since been buried alongside her mother in New Jersey.