The law firm and the congressional committee that investigated drugs in baseball are fighting pitching standout Roger Clemens over access to evidence collected against him, a development that could delay the trial on charges he lied about being a user.

The House Oversight and Government Reform Committee and the firm that produced the Mitchell Report filed motions in federal court in Washington on Friday to quash Clemens' subpoenas. Clemens wants to see their evidence accusing him of using steroids and human growth hormone, likely looking for weaknesses or inconsistencies in witness testimony to defend himself in the criminal trial scheduled for July.

In 2006, Major League Baseball Commissioner Bud Selig hired former Sen. George Mitchell and the DLA Piper firm he worked for at the time to investigate allegations that players used drugs. The Mitchell Report issued Dec. 13, 2007, accused several players including Clemens.

The House committee held hearings on the report in February 2008. Clemens testified that he never used performance-enhancing drugs during 23 seasons, in which he recorded 354 wins and 4,672 strikeouts and won seven Cy Young awards. Prosecutors say evidence proves that he did and charged him with perjury, false statement and obstruction of Congress.

Clemens wants DLA Piper to turn over material related to its interviews with his longtime personal trainer Brian McNamee, who told investigators he injected Clemens with performance-enhancing drugs; admitted steroid user and retired player Jose Canseco; and former New York Mets clubhouse attendant Kirk Radomski, who McNamee said provided the drugs Clemens used.