Celebrity Web sites reported that Britney Spears returned late on Wednesday promising rehabilitation, which she had taken off earlier that day after barely 12 hours of treatment.
Britney's' spokesperson did not return any calls for comment on the reports, which followed a turbulent week that has seen one of the world's best-known pop stars in and out of rehab three times and shaving her own head.
The Web site of syndicated TV show Extra said there was video showing her driving through the gates of the luxury Promises center with her mother.
Other reports said Spears returned after seeking a meeting with Federline on Wednesday but being denied entry to the house where he is staying with their children, Jayden James, 5 months old, and Sean Preston, 17 months old.
Spears filed for divorce in November after two years of marriage and both she and Federline are seeking custody.
Several reports said Spears returned for a full 30-45 days of treatment after Federline gave her a last chance to get help or risk losing custody of the children.