A jury on Monday acquitted Major League Baseball pitching great Roger Clemens of all six criminal counts against him in a trial on charges that he lied to Congress when he denied using performance-enhancing drugs.

Clemens, dressed in a beige suit, blue shirt and tie, showed little outward emotion as the verdict was read, but choked up during brief comments after he emerged from the federal courthouse in Washington.

"It has been a hard five years," Clemens said, as he thanked his wife, family and teammates. "I put a lot of hard work into that career. I appreciate my teammates that came in and all the emails and phone calls from my teammates."

Jurors deliberated for a total of about 10 hours before coming to a decision. The verdict was another setback for prosecutors who insisted on pursuing the case even after their first effort ended in a mistrial.

One of the greatest pitchers in baseball history, Clemens was charged with one count of obstruction of Congress, three counts of making a false statement and two counts of perjury. He did not take the stand in his own defense during the two-month trial.

If convicted, Clemens would have faced a maximum prison term of 30 years, though under federal sentencing guidelines he most likely would have received 15 to 21 months.

Clemens' lawyer, Rusty Hardin, mouthed "thank you" as jurors read the verdict and then shook hands with his client. He later said "justice won out" in the closely watched trial.

"It's a day of celebration for us," he said.

Clemens' first trial -- on federal charges of lying in 2008 to a congressional committee that was investigating drug use in baseball when he said he did not use performance-enhancing drugs -- ended in a mistrial after just two days of arguments.

In that case, prosecutors showed jurors a video clip that included material the judge had banned from the trial unless the information was raised by Clemens' defense team.

The current trial featured 46 witnesses over 26 days of testimony, a slow-paced case that frustrated observers and U.S. District Judge Reggie Walton, who advised lawyers on both sides to move more quickly. Two jurors were dismissed for falling asleep.

Witnesses included one-time teammates, scientific experts and central figure Brian McNamee, Clemens' former trainer, who said he injected Clemens with anabolic steroids and human growth hormone between 1998 and 2001.

McNamee worked with Clemens when the pitcher played for the Toronto Blue Jays and later the New York Yankees.

McNamee testified that he kept needles, cotton balls, a broken steroid ampoule and other medical waste from injections for Clemens. Prosecutors said some of the items contained Clemens' DNA and traces of steroids.

Clemens' lawyers said McNamee contradicted himself throughout the investigation and trial and had not just lied about his motives for keeping medical waste he later gave to authorities, but "made up this story" about doing so to keep his wife off his back.

Known as "The Rocket," Clemens played for four teams over a 24-year career and won 354 regular season games. He is a seven-time winner of the Cy Young Award for best pitcher -- success, his lawyers said, that was due to hard work.

Doping, or using performance-enhancing substances in professional sports, is not in itself a federal crime. But the U.S. government has chosen, with mixed results, to pursue cases against athletes it believed had either committed fraud or lied when called to testify about using drugs.

The Clemens verdict is the government's second high-profile setback in recent months.

In February, prosecutors dropped a two-year investigation that centered on whether seven-time Tour de France champion Lance Armstrong and his teammates cheated the sponsor of their bike racing team with a secret doping program.

The U.S. Anti-Doping Agency (USADA) last week notified Armstrong that it had started formal procedures against him over allegations he used performance-enhancing drugs during his record-breaking career. Armstrong has always denied doping.

(Editing by Paul Thomasch, Christopher Wilson and Jim Loney)