NEW YORK - Roger Clemens’ lawyers have hired private investigators to try to challenge the credibility of Brian McNamee, who said in the Mitchell Report that he had injected Clemens with steroids, the New York Times reported Thursday.

The investigators might have a tape of McNamee contradicting his testimony about Clemens, the New York Times reported, citing an unnamed lawyer familiar with the case.

The lawyers are investigating accusations in the Mitchell Report that say the star pitcher used steroids and human growth hormone.

Clemens was the biggest name in this month’s report by former Senate majority leader George Mitchell that detailed widespread use of performance-enhancing drugs in baseball. The seven-time Cy Young Award winner has repeatedly denied using steroids or HGH.

“On Roger’s behalf, we are investigating the allegations about him contained in the Mitchell Report,” Clemens’ attorney, Rusty Hardin, said Wednesday in a statement. “To our surprise, we have identified several people who logic dictates the Mitchell team should have talked to but did not. That’s troubling. We are asking questions and we encourage the news media to do the same.”

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Many of the allegations against Clemens in the Mitchell Report came from McNamee, his former trainer. According to the report, McNamee said he injected Clemens with steroids in 1998 while with the Toronto Blue Jays, and steroids and HGH in 2000 and 2001, while with the New York Yankees.

Clemens plans to be interviewed for an episode of CBS’ “60 Minutes” that is scheduled to air Jan. 6. The pitcher will be available to answer questions from other reporters that day in Texas, said Hardin’s spokesman, Joe Householder.

Hardin said the “60 Minutes” interview was slated to take place this week at Clemens’ home in Texas, The New York Times reported on its Web site Wednesday.

“We are convinced the conclusions in Mitchell’s report are wrong and are investigating the findings ourselves,” Hardin told the newspaper.

Clemens posted a video Sunday on the Internet repeating his denials of the allegations against him in the report. McNamee’s attorney, Ed Ward, has said his client stands by the accuracy of the information he gave to Mitchell.  

McNamee hasn't talked to Clemens since the Mitchell Report came out, McNamee's lawyer, Earl Ward said, the New York Daily News reported.

"Brian would be open to (talking to Clemens), certainly," Ward said, the Daily News reported. "I don't know if Roger would. But Brian would be open to it because he knows what he's been saying all along is honest and truthful and he'd want Roger to understand he was obligated to tell the truth.

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"The bottom line is he did not want to implicate a friend and a baseball icon in a steroid scandal," Ward said, the newspaper reported. "He was asked to tell the truth and he has. That's always been his position since Day 1."

McNamee "sticks by what he told Senator Mitchell," Ward said, the Daily News reported. "I don't think he has anything additional to add to what he told Mitchell and federal investigators. It was accurate."

McNamee also has not been contacted to testify in front of Congress, Ward said, the newspaper reported.