NEW YORK -- The top Democrat on the House Oversight and Government Reform Committee says the NFL players' union "is now holding HGH testing hostage" and that could "force Congress to intervene."

Rep. Elijah Cummings of Maryland says in a statement emailed by his office to The Associated Press on Thursday that the "NFL Players' Association continues to disregard its promise to implement HGH testing."

The oversight committee held a hearing in December to take a look at the science behind blood tests for human growth hormone. HGH is a banned performance-enhancing drug that is hard to detect and has been linked to health problems such as diabetes, cardiac dysfunction and arthritis.

Two full NFL seasons have passed without a final agreement on HGH since the August 2011 labour deal paved the way for testing.