Roger Clemen's trial for perjury collapsed on Thursday after prosecutors showed jurors previously excluded evidence.

Baseball star Roger Clemens who was named the sport's best pitcher seven times was indicted last year for allegedly lying to Congress about using performance enhancing drugs.

U.S District Judge, Reggie Walton abruptly declared a mistrial on the second day of the testimony concluding that federal prosecutors had unduly prejudiced jurors by showing them information on a videotape that the judge had specifically precluded from the case.  The evidence in question was a testimony from Yankee pitcher Andy Pettitte's wife, Laura, which was considered inadmissible hearsay and ruled out by the judge.

The error left Judge Walton extremely angry. Government counsel can't do what it thinks it can and get away with. Any first year law student should know that, he said.

The mistrial was a major setback for the government, which spent a year preparing the case. Four days were spent on selecting a jury, reported Reuters.

Walton said the parties would have to discuss whether retrying Clemens would violate the constitutional protection against double jeopardy, which protects an individual from being tried twice for the same offenses. A hearing on the double-jeopardy issue will be on September 2 but no new possible trial date was set, according to Reuters.

I'm not going to put this man's liberty in jeopardy, Walton said, adding that prosecutors could not persuade him to reconsider his decision. You're not going to be able to convince me.

Clemens had been charged with lying to Congress about his use of performance enhancing drugs. He denied taking steroids and human growth hormones from 1998-2001.

Clemens, 48, pitched for four teams during his 24-year career in baseball, including the New York Yankees, Boston Red Sox, Toronto Blue Jays and Houston Astros. He was one of only four pitchers to strike out more than 4,000 batters.

I was one of those people who urged the prosecution of athletes believed to be juicers, whether it was for perjury or tax fraud or whatever. I believe it is critically important to our judicial system that people not get away with lying under oath, said Cindy Boren in her blog on the Washington Post. I'm less concerned about juicing because, frankly, I think everybody did it and maybe still does. What I'm more interested in is the scope of doping. I believe it is terribly important to know just what went on - and may still be going on. I just want the facts.