A House oversight committee is threatening to turn up the heat on the NFL and its players for promising to test for human growth hormone, or HGH, but never implementing a plan to do it.

In a letter to National Football League Players Association, the top Democrat and Republican on the House Oversight and Government Reform Committee wrote: "We intend to take a more active role to determine whether the position you have taken--that HGH is not a serious concern and that the test for HGH is unreliable--is consistent with the beliefs of rank and file NFL players."

Committee Chairman Darrell Issa and Ranking Member Elijah Cummings added: "Despite being the first of the major professional sports leagues to agree to test for HGH, the NFL has now fallen far behind its counterparts in implementing the agreement." They added, "While NFLPA management may not believe that HGH is a problem in the NFL, the words of your athletes suggest otherwise. We hope the facts collected by the committee will provide you and the NFL with the information necessary to resolve this matter."

The committee has taken the issue seriously, holding a hearing last month to discuss the science of testing for HGH.

The duo noted that Major League Baseball has moved to implement in-season testing for HGH in its players which they hope will pressure the NFL and NFLPA to follow suit.