Spears was one of the stars whose privacy was breached
An ex-Los Angeles hospital worker has pleaded guilty to selling medical files of stars including Britney Spears and Farrah Fawcett to a newspaper.
Prosecutors said Lawanda Jackson had been paid at least $4,600 (£3,000) by the National Enquirer for the details from the UCLA Medical Center.
They said Jackson, due for sentencing in May, had worked there for 32 years, only selling records in recent years.
The National Enquirer was not available for comment.
The paper began depositing cheques in the account of Jackson's husband in 2006, prosecutors said.
Jackson, 49, resigned from her administrative job in July 2007 before she could be sacked, they added.
She faces up to 10 years in prison and a $250,000 (£165,000) fine for breaking medical privacy laws for commercial purposes.
The UCLA Medical Center said in a statement that it would not comment on the Jackson case but that it would continue to co-operate with authorities in patient privacy investigations.
Jackson and state officials had revealed that actress Fawcett and singer Spears were among those whose privacy had been breached.
Back in April, a lawyer for Fawcett said that a diagnosis of cancer and details of her treatment had appeared in the National Enquirer.
United States Department of Justice spokesman Thom Mrozek said an investigation into privacy breaches was focusing, in part, on the role of the media.
"Certainly there is possible culpability at media outlets if we can determine that they were knowingly paying for the illegal access of celebrity files," he added.