McNamee originally put himself in Clemens' crosshairs when he signed a proffer agreement with federal prosecutors, stipulating that he could not be charged with steroid distribution as long as everything he told the prosecutors was truthful. He also was asked to cooperate with the investigation led by former Sen. George Mitchell on behalf of Major League Baseball, which made public McNamee's claims that he injected Clemens with steroids and growth hormone in 1998, 2000 and 2001.
Congress decided to hold its hearing after Clemens publicly challenged the veracity of the Mitchell report.
Clemens filed a defamation lawsuit against McNamee last January. McNamee's attorneys have since argued to have the suit thrown out. Last month, they filed a defamation suit on McNamee's behalf against Clemens.
Clemens is the latest professional athlete to be accused of using steroids or performance-enhancing drugs, and see his case dragged back into the media spotlight after he denied it.
In January the slugger Mark McGwire admitted that he in fact had used steroids during his baseball career, though he dodged the question in a hearing on Capitol Hill. "it was a wrong thing what I did. I totally regret it," said McGwire.
Now, however, the spotlight is firmly on Clemens as he gears up for a trial that could end up determining his reputation, his freedom, and his place in baseball history.