From the official site:

In a letter sent to Hardin on Sunday, Waxman expressed concern with Hardin's comments published in The New York Times. The attorney reportedly said that it would be "unbelievable" and "brazen" if a federal agent, Jeff Novitsky, attended a committee hearing scheduled for Wednesday.

The article also reported that Hardin said, "I can tell you this: If [Novitsky] ever messes with Roger, Roger will eat his lunch." ...

"If today's quotation is accurate, however, it goes beyond any personal enmity that exists between Roger Clemens and Mr. McNamee," Waxman wrote. "I do not know your intent in making this statement, but under one interpretation, it can be seen as an attempt to intimidate a federal law enforcement official in the performance of his official duties."