Defense attorneys in the perjury trial of legendary pitcher Roger Clemens attacked the government’s presumptive star witness Monday, saying trainer Brian McNamee’s past contains “more dirt than a pitcher’s mound.”

That line came in a filing from lead defense attorney Rusty Hardin, whose team objected to the prosecution’s efforts to keep out information about McNamee’s troubled background.

Roger Clemens walks near the federal courthouse in Washington, D.C., April 30, 2012. (Yuri Gripas/Reuters)

Clemens, on trial in the District’s federal court for allegedly lying to Congress when he denied using performance-enhancing drugs during a 2008 hearing, faces up to 30 years in prison. Federal prosecutors want to preclude unflattering and potentially damaging information about McNamee, who is expected to testify that he injected Clemens with steroids on numerous occasions.

They want U.S. District Judge Reggie Walton to declare the information “off-limits” to prevent the defense team from asking McNamee about it during his cross-examination.

The defense wants to allow the jury to hear evidence of McNamee’s alleged drug problem, financial struggles, blemished record as a New York City police officer and his involvement in a criminal investigation in Florida. McNamee lied to authorities in a 2001 investigation involving the sexual assault of an unconscious woman at a St. Petersburg hotel.

“There is no question that Mr. McNamee committed obstruction of justice...the very crime the government seeks to convict Mr. Clemens of in this case,” according to Clemens’s lawyers.

In the courtroom Monday, federal prosecutors played recordings of Clemens’s denials in his interview with Congressional staffers and his testimony to Congress while the former All-Star took copious notes on a legal pad.

The defense sought to challenge the legitimacy of the 2008 Congressional hearing that examined whether Clemens had used performance-enhancing drugs. Clemens’s lead lawyer quizzed the committee’s former staff director, Phil Barnett, about whether Clemens appeared voluntarily.

“Putting him up there next to his accuser and trying to let the world decide right or wrong is not a legitimate function of Congress,” Rusty Hardin said in an exchange with Judge Walton out of earshot of jurors. “It was solely to get Roger Clemens.”

Barnett said Congress was trying to reconcile a report by former senator George Mitchell that named Clemens and other ballplayers as steroid users with Clemens’s public denials.

In the taped interview, Clemens was quizzed about his relationship with McNamee, his former strength coach. McNamee told Congress that he injected Clemens on several occasions with steroids, but Clemens said the injections were vitamins.

Clemens was asked in his deposition with the House Committee on Oversight and Government Reform why McNamee, not a team doctor, was injecting him, and whether the shots could have been tainted with steroids.

“I have no reason to believe he was doing anything harmful,” Clemens said, later describing McNamee as “great.”

Clemens also described in detail his account of the use of human growth hormone known as HGH by his wife, Debbie, who he said was injected by McNamee in the bedroom of the couple’s Houston home. Clemens said he was not at home at the time, and was concerned that McNamee had “drugs on the property.”

Clemens said he rifled through McNamee’s belongings, which the trainer had left behind, but did not find any HGH.

“Deb cried about it; she apologized to me about it,” Clemens said. “It’s embarrassing because she thinks she’s been pulled into a trap.”

Clemens’s account is at odds with McNamee’s story that Clemens was present when McNamee gave his wife the shot.

This item has been updated.

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