"Put it this way, I don't watch her on the TV. I change the channel," Johann, 58, told Radar. "The fame around her became a nightmare, the negativity it brought. I don't know what she's doing now, and I don't want to know."
Christina, 37, publicly opened up about her troubled past in 2009, blaming her problems on her father, Fausto Xavier Aguilera, 68.
"The pain at home is where my love for music came from," the singer insisted.
Johann, who lives with Christina's father in Staten Island, N.Y., said his brother is heartbroken he hasn't mended his now-fractured relationship with his daughter.
"It's a touchy subject. Fausto's very reserved," Johann said. "Christina will always be in my heart, but it is difficult."
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