The six-count indictment alleges that Clemens obstructed a congressional inquiry with 15 different statements made under oath, including denials that he had ever used steroids or human growth hormone. The New York Times first reported the indictment.

Former Rep. Tom Davis of Virginia, the top Republican on the House panel at the time of Clemens' testimony, called it "a self-inflicted wound."

Clemens had been prominently mentioned in the Mitchell Report, Major League Baseball's own accounting of its steroid problem, and he went to Capitol Hill on his own to clear his name.

"Clemens was not under subpoena. He came voluntarily," Davis said. "And I sat there in the office with [committee chairman] Henry Waxman and said, 'Whatever you do, don't lie.' "

"When a witness, such as Roger Clemens, lies, as I think he did, he should be held accountable," said Rep. Henry Waxman, D-Calif., the House committee's chairman at the time of the baseball star's testimony. Waxman said the indictment will "help end the use of steroids and performance enhancing drugs in professional sports."

Despite that, Clemens was sticking to his story Thursday. He insisted he was telling the truth, again denying any wrongdoing on or off the field.

"I never took HGH or Steroids. And I did not lie to Congress," Clemens said on Twitter. "I look forward to challenging the Governments accusations, and hope people will keep an open mind until trial. I appreciate all the support I have been getting. I am happy to finally have my day in court."

The U.S. Attorney's Office said it would have no comment beyond the indictment itself.

Clemens faces a combined maximum sentence of 30 years in prison and a $1.5 million fine, though under U.S. sentencing guidelines the recommended range of time is 15-21 months.

"Roger is looking forward to his day in court," Clemens lawyer Rusty Hardin told a news conference. "He is happy this has finally happened. We have known for some time this was going to happen. We'll let everything get taken care of in court."

Hardin said federal prosecutors made Clemens a plea offer but he rejected it. Hardin declined to comment on details of the proposed plea deal -- which ordinarily involves admitting to a crime while avoiding the scenario of a multiple-count indictment as happened in the Clemens case.

Clemens is just the latest superstar to be ensnared in baseball's steroid scandal. All-time home run king Barry Bonds is scheduled to go on trial in March on charges of lying to a federal grand jury when he said he never knowingly used performance-enhancing drugs. Slugger Mark McGwire admitted earlier this year to using steroids.

What once seemed to be a he-said vs. he-said dispute between Clemens and his former trainer, Brian McNamee, once the New York Yankees' strength and conditioning coach, escalated into a federal case. The grand jury heard testimony from McNamee, who gave federal authorities syringes he said were used to inject Clemens with drugs.

Hardin said that although many have argued that Clemens should simply admit he took steroids, "the problem is nobody ever talks about what he should have done if he didn't do it."

"And he didn't do it and he's adamant about that and always has been. Today is just another continuing part of that saga," Hardin said.

Clemens, who turned 48 this month, ranks ninth on the career list with 354 victories. He once was considered a certain first-ballot Hall of Famer, but getting in at all is now in question.

"In my opinion, he's a Hall of Famer. Period," said New York Yankees slugger Lance Berkman, who played with Clemens in Houston. "Whatever you want to say about the guy, he belongs in the Hall of Fame. In my opinion, legacy-wise, I guess that's up to -- I mean, 200 years from now, who cares?

"But in the short term, I guess, he may have some things to address," Berkman said. "He's a big boy. He'll face up to whatever it is. But it doesn't change my opinion of him at all."

Yankees catcher Jorge Posada, who played with Clemens on two World Series championship teams, said he would back his former teammate.

"I'm going to support him and I'm going to be behind him and that's all I can say," Posada said.

MLB did not comment on the indictment. But many in the game saw it as further validation of the Mitchell Report, released in December 2007.

Clemens was singled out by name 82 times in the 409-page report, compiled by former Senate Majority Leader George Mitchell. Much of the information on Clemens came from McNamee.

Former MVP Jose Canseco, who has admitted his own steroid use and accused others, was the most-mentioned player in the Mitchell Report with 105 references.

"I am saddened to hear of the indictment of my friend and former teammate, Roger Clemens," Canseco said in a statement through his attorney. "I am not aware of any use of steroids by Roger."

Four days after the report was released, Clemens issued a categorical denial in a statement through his agent.

"I am disappointed that my 25 years in public life have apparently not earned me the benefit of the doubt, but I understand that Senator Mitchell's report has raised many serious questions. I plan to publicly answer all of those questions at the appropriate time in the appropriate way. I only ask that in the meantime people not rush to judgment," Clemens said.

Clemens and McNamee testified under oath at the 2008 hearing before a House committee and contradicted each other about whether the pitcher had used PEDs.

In 2008, Roger Clemens told a congressional committee he had never used steroids or HGH. Mark Wilson/Getty Images

McNamee has said he injected Clemens more than a dozen times with steroids and HGH from 1998 to 2001. Clemens says McNamee was lying.

Some of McNamee's evidence is believed to include bloody gauze, vials and needles that he claims contained steroids and Clemens' DNA. McNamee kept the decade-old evidence in a FedEx box at his New York home and handed it over to investigators after the probe began.

Clemens sued McNamee for defamation, but a federal judge in Texas dismissed most of Clemens' claims against McNamee last year. Earlier this month, a federal appeals court affirmed the decision.

McNamee has filed a defamation suit against Clemens in federal court in New York.

"I hate to see anyone get in trouble, but you get what you deserve if you don't tell the truth in front of Congress," said Kirk Radomski, who admitted providing performance-enhancing drugs to McNamee. "I'm glad for Brian [McNamee], because Brian can start moving on with his life now. People understand that he told the truth. The only one who lied in this whole matter was Roger."

"As far as we're concerned, it's vindication," Earl Ward, one of McNamee's attorneys, said of the indictment.

"This all came about, ultimately, because of Roger's arrogance. He was the one who demanded the Congressional hearing. He's in this position now because of his arrogance," Ward told ESPN.