AP file photo of Roger Clemens.
WASHINGTON (AP) -- Defense lawyers for Roger Clemens say they may challenge key physical evidence that his former strength trainer, Brian McNamee, has provided to prosecutors in the famed pitcher's perjury trial.
The lawyers told U.S. District Judge Reggie Walton at a hearing Friday that unspecified developments that prosecutors made them aware of over the last few weeks raised issues about the chain-of-custody of the evidence.
McNamee has said he repeatedly injected Clemens with steroids and human growth hormone, and saved some of the needles and gauze. Clemens' lawyers say that if the government can't prove the chain-of-custody, they will challenge McNamee's evidence, which is central to the prosecution's case.
Clemens is accused of lying to Congress when he said he never used performance-enhancing drugs. Jury selection in the trial begins Monday.
From the Associated Press