The boyfriend of Bobbi Kristina Brown has reportedly blamed drug use on the bathtub accident which left her in a medically-induced coma.

According to TMZ, a phone conversation between Nick Gordon and a relative of Brown was secretly recorded on 22 February 2015, three weeks after she was found unresponsive in a bathtub at her Roswell, Georgia home on 31 January.

Gordon, who is reported to have been unaware the conversation was being recorded, allegedly said: "I'll tell you the honest truth, Krissy, she was under a lot of stress and we were all doing drugs and you know, all, all drinking, bro."

Referring to substance abuse, the 27-year-old reportedly added: "She just did too much man. She, listen, listen bro. I will officially stay [away] from bathtubs forever, I'll tell you that."

Reports have since emerged that if Brown loses the fight for her life, Gordon will be part of a criminal investigation with police allegedly believing he was involved in the incident.

However, in the phone conversation, he appears to be protesting his innocence, stating: "When Krissy wakes up she'll tell the truth to everybody. Everybody will feel stupid as f**k...

"You know Krissy got in an accident two days before this happened and the man is in critical condition right now."

He reportedly adds: "If they take her off that life support, the police are going to have to take me down bro."

Bobbi Kristina's aunt Pat Houston announced on 24 June that the daughter of the late Whitney Houston has been taken off life support and moved to the Peachtree Christian Hospice in Duluth, Georgia.

Bobbi Kristina's father Bobby Brown performed on stage with his group New Edition during a Fourth Of July celebration concert in Atlanta. TMZ reports the 46-year-old singer struggled to get through the performance.