A former bodyguard for Britney Spears was the much-hyped "secret witness" in her custody battle with Kevin Federline today. Tony Barretto was prepared to testify about "issues of nudity by Ms. Spears, drug use and safety issues involving the children" that he witnessed as her bodyguard before being fired on May 17, says Barretto's attorney. Instead of testifying, his written allegations were entered into court as evidence. Spears's lawyer, Laura Wasser, strongly denied allegations of drug use by her client. "He isn't a credible witness," said Wasser after a two-hour closed-door hearing on Monday. The hearing was the last for Wasser, who stated she's officially stepping aside as Spears's attorney. Spears's new lawyer will be Marci Levine. "Britney will be in excellent hands" with Levine, Wasser said. "I don't want anyone to perceive that we're dumping Britney," Wasser added. "In a lot of attorney-client relationships, there comes a time when some fresh blood is necessary." Wasser also confirmed that Spears and Federline's current 50/50 custody arrangement for Sean Preston and Jayden James will remain in effect for now. She also added that many of the popstar's associates have already been deposed after being issued subpoenas to testify about Spears's parenting skills.