Sources: McNamee gave samples to rule himself out as tissue source

Brian McNamee, the personal trainer who accused Roger Clemens of using steroids and human growth hormone last year, gave a DNA sample to FBI agents in August to bolster his accusation, two sources told ESPN.

Investigators hope to establish whether syringes provided by McNamee in February contain Clemens' DNA and were used to inject him with performance-enhancing drugs. Clemens has been under investigation for perjury since he testified to Congress in January that he had never used steroids or growth hormone, despite the testimony of McNamee and Clemens' former teammate Andy Pettitte.

If the U.S. Attorney's office in Washington can establish that Clemens used those needles to inject himself with the drugs, it could be the basis of a perjury case. McNamee's accusations were first made public last December in former Sen. George Mitchell's report on doping in Major League Baseball.

The sources were not sure whether Clemens had provided a DNA sample, but said that McNamee and his attorneys, Earl Ward and Richard Emery, were all asked to provide samples in order to rule out the three men as having been the source of any tissue found on the needles.

Clemens' attorney, Rusty Hardin, did not return calls from ESPN early Monday, but has said that even if the needles contained Clemens' DNA, there would be no way to prove that he actually used the needles to inject himself, or that the syringes contained steroids or HGH when they were used. Law enforcement sources said they believe that if the needles contain certain tissue with Clemens' DNA that could have come only from an injection, then the evidence could be damning.

"As I have said from the beginning, we are willing to cooperate with any aspect of the government's investigation," The New York Times quoted Hardin as saying Monday.

Sources said they were not aware of any other activity in the case since August, but Clemens is also pursuing a defamation lawsuit against McNamee.

U.S. District Judge Keith P. Ellison recently ordered McNamee's attorneys to provide evidence that McNamee was required by federal prosecutors to share information with Mitchell. The U.S. Attorney's office in San Francisco is expected to submit an affidavit in support of McNamee before the Dec. 18 deadline, which could potentially help McNamee's motion for dismissal.

T.J. Quinn is a reporter for ESPN and can be reached at tjquinn31@yahoo.com.