As Nick Gordon grieves the death of girlfriend Bobbi Kristina Brown, his legal woes just went from bad to worse. TMZ reports that the 22-year-old has been accused of murdering the only child of the late Whitney Houston and r'n'b star Bobby Brown by giving her a "toxic cocktail" of drugs before putting her face down in the bathtub at their Georgia home.

Bobbi Kristina passed away on 26 July 2015 at Atlanta's Peachtree Christian Hospice, almost six months after she was found unconscious. She was laid to rest beside her mother, who died at The Beverly Hills Hotel, California in 2012.

In June, Brown's court-appointed conservator filed $10m (£6.4m) lawsuit against Gordon alleging that he stole money from her and subjected her to domestic abuse. An amendment has now been made to the filing which also gives a chilling timeline of what they claim happened in the hours leading to the moment she was found face down in her bathtub on 31 January.

"I am deeply saddened by the recent death of Bobbi Kristina Brown. I extend my sincerest condolences to all of her family. 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," Bobbi Kristina's conservator Bedelia C. Hargrove told People magazine, in a statement.

"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."

According to the complaint, Gordon arrived at Bobbi Kristina's townhouse after an all-night cocaine and drinking binge and become irate after reviewing camera footage.

The papers obtained by TMZ, claim Gordon and his girlfriend then "became embroiled in a loud argument" that ended in the master bedroom.

"The defendant screamed at Bobbi Kristina accusing her of cheating, going so far as to call her a 'whore', a 'bitch', and other names," the papers allege. "The argument lasted for about thirty minutes and then everything abruptly became quiet."

Their argument is said to have gone from room to room, after which Gordon allegedly administered a "toxic cocktail" to Bobbi Kristina that rendered her unconscious, before putting her face down in a tub of cold water and coming out of the master bedroom wearing different clothes.

Bobbi Kristina's conservator claims that another female was at the townhouse at the time, and after leaving the master bedroom, Gordon laid his head on female guest's ankle and stated, "now I want a pretty little white girl like you".

Fifteen minutes later, another guest in the house allegedly found Brown in the bathtub, and according to the lawsuit she was "unresponsive, unconscious with a swollen mouth and a tooth hanging loosely from her mouth".

Gordon then came in and said "clean up, clean up" to the guests, who attempted to give her mouth-to-mouth resuscitation, the document said.

However, legal representatives for Gordon have hit back branding the claims as "slanderous and meritless".

"The recent lawsuit against Nick is 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," Gordon's legal team Joe Habachy and Jose Baez said.

"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."