Jamie Spears told Fox News that the troubled singer is "a sick little girl ... we're just trying to take care of her, and other than that I have no comment."
Speaking Thursday from his Louisiana home, Spears said his daughter's issues are "not about what other people think," adding that he and his ex-wife, Lynne, are "concerned about our daughter."
Meanwhile, there were reports Friday that Spears' ex, Kevin Federline, had visited Spears in rehab in Malibu.
The pop star's manager confirmed to The Associated Press on Thursday that Spears is at the Promises Malibu drug and alcohol rehabilitation center in Southern California. He's not giving any other details.
The video, shot by the paparazzi agency X-17, shows Spears pounding a photographer's car with an umbrella, her face contorted in rage. She was apparently upset that the paparazzi followed her to estranged husband's house.
Spears was wearing a gray pullover, running shorts, white sneakers — and a pearl necklace. To see the photos and video, click here.
Spears' downward spiral has been the topic of tabloids and blogs since her split from Federline in November.