Bobbi Kristina was found face-down and unconscious in her bathtub in late January, and has remained in a medically-induced coma ever since.
The medical emergency came nearly three years after Houston drowned in a hotel bathtub.
"Auntie Whitney was murdered not drowned. That’s a fact"
Now Jerod Brown, the cousin of Bobbi Kristina, has taken to Facebook to make a series of wholly unsubstantiated claims about his Aunt Pat - aka Whitney Houston's sister-in-law - in which he accuses her of their murder.
He said: "Auntie Whitney was murdered not drowned. That’s a fact. Now the whole bathroom plot shows up again w/ Bobbi Kristina’s situation.
"C’mon are you people that bold to try to perform this act again on my family.
"And the public believes whatever these people put in their faces, i mean it is convincing if you’re not on the inside.
"However, I will let it be known Kristina has always had suspicion about Pat Houston. Soon evidence will be handed over to assist this investigation [sic]."
Pat is married to the late Whitney Houston’s brother, Gary.
In the wake of her death, Pat and Gary became two of the co-executors of Bobbi Kristina’s $20 million trust - and the pair have been by her bedside as she fights for her life.
It is worth noting that police never found any signs of foul play with Whitney's death, which was officially attributed to drug use and heart issues.
And, while they have not yet ruled out foul play in Bobbi Kristina's health crisis, the investigation is reportedly centred on Nick Gordon, not Pat.