Teefey said the late singer was like a daughter to him and he always wished the best for her, reported E! online.
"Words cannot begin to describe the pain I am feeling. I learned this business through the eyes of a father and Christina was like a second daughter to me.
All I wanted to do was assist her in achieving her musical dreams while protecting her from the pitfalls associated with the business. I never could have imagined this horrific event being one of the pitfalls needing to be avoided," he wrote on GoFundMe.
"As family, mother, father, and brother made the ultimate family sacrifice to support Christina on her musical journey. They did nothing but love her and support her as family the best they knew how, the only worry I want them to have at this point is that of recovery," he added
The campaign has raised over USD 33,000 so far, exceeding the goal of USD 4,000.