Bobbi Kristina Brown and Nick Gordon
Bobbi Kristina Brown and Nick Gordon's relationship was heavily criticised by her family and the mediaFrazer Harrison/Getty

Lawyers representing the estate of Bobbi Kristina Brown claim the 22-year-old died as a result of a "violent altercation" with her boyfriend Nick Gordon. According to court documents filed in Fulton County, Brown died "after a particularly violent altercation with the Defendant which left her battered and bruised, with a tooth knocked out."

It is alleged that Gordon then "placed her in the bathtub unconscious, after he injected her with a toxic mixture" of drugs, WSB-TV reports. Police interviews with friend Max Lomas, who was at the town home on the day of the January 31, revealed that Gordon had been "out all-night on a cocaine and drinking binge," prior to the alleged assault.

In earlier statements Gordon, who is also accused of trying to cover up the fight in the bathroom by changing his clothes, admitted that he went out on the night in question, and "reviewed video footage and then had an argument with Ms. Brown and then changed his clothes."

However, he denies all the allegations against him, including accusations of assault, battery, causing emotional distress and stealing Miss Brown's money. Gordon's lawyers have dismissed the allegations claiming that the charges have been made in an attempt to smear his name, adding that there is no evidence of an altercation between the two.

According to TMZ, his legal team assert that the results of Brown's autopsy have been sealed to both sides and that neither is privy to any such information that might indicate a cause of death or details of the circumstances leading up to when Brown was found unconscious in the bath tub.

The latest claims come amid rumours that Gordon is due to be arrested on murder charges after reports that a secret grand jury is due to be convened by a district attorney judge in Georgia with the intent of charging Gordon with the death of Whitney Houston's daughter.

The Fulton County Medical Examiner's Office told US Weekly that the cause of Brown's death had been officially determined, but the findings were ordered to remain private by a judge. The magazine claims that Gordon will be charged with criminal charges 'very soon' and the judge is consulting with legal experts to see if murder charges would stick.

Bobbi Kristina Brown was placed in a medically-induced coma and transferred to a specialist rehabilitation facility after she was found face down and unresponsive in the bath tub of her Georgia home. She died on July 26 at the Peachtree Christian Hospice, Duluth, six months later.

A civil suit was filed in June and the attorney for the 22-year-old's estate amended the complaint to include an accusation of 'wrongful death'. "We will leave no stone unturned in seeking justice for Bobbi Kristina Brown,"' said a statement from her legal team.