House Republicans said Tuesday that the Food and Drug Administration should have acted years earlier to close the Massachusetts pharmacy responsible for a deadly meningitis outbreak tied to contaminated medications.

A report issued by Republicans blasts the FDA for failing to act on years of complaints about problematic drugs and practices at the New England Compounding Center. The compounding pharmacy produced tainted pain injections that have sickened more than 700 Americans and killed 53 others.

The wave of infections was first identified in September and grew into one of the deadliest medication-related outbreaks in U.S. history. The NECC halted operations in October and faces more than 100 lawsuits in federal court.

But more than six months later, lawmakers in Washington continue to debate whether the public health crisis could have been prevented.

Republicans on the House subcommittee investigating the outbreak said the FDA should have closed the NECC based on complaints from doctors, patients, hospitals and drug distributors. The FDA first inspected the pharmacy in 2002 and issued a warning letter in 2006 for mass producing copies of manufactured drugs. Beginning in 2007 and continuing through 2012, the FDA received complaints about the company from anonymous informants and state pharmacy regulators, according to internal documents released by the committee.

“Ten years of warning signs, alarm bells, and flashing red lights were deliberately ignored,” said Rep. Tim Murphy, R-Pa., who chairs the House Energy and Commerce Subcommittee on Oversight and Investigations. Murphy and other Republicans point to correspondence in thousands of pages of FDA documents turned over to the committee.

FDA Commissioner Margaret Hamburg reiterated Tuesday that her agency needs clearer authority to go after the compounding industry, which has challenged the FDA’s authority in court since the 1990s.

In testimony, Hamburg said the agency is working to crack down on compounding pharmacies, despite conflicting laws and court decisions that govern the space.

“I wish we had been more aggressive, and I can assure you that we are being more aggressive now,” Hamburg said.

Republicans pressured Hamburg to explain a 2011 FDA decision to suspend routine inspections of compounding pharmacies, including the NECC. Hamburg said agency lawyers recommended the halt in enforcement due to legal questions about the agency’s authority to police compounding pharmacies. Hamburg told lawmakers she was unaware of the policy at the time.

“I regret that I was not more fully aware,” Hamburg said.

Compounding pharmacies mix customized medications based on doctors’ prescriptions, and have traditionally been overseen by state pharmacy boards. But in recent years, the FDA has tried to police larger compounders like the NECC, which operate more like manufacturers by mass producing drugs and shipping them across state lines.

Last week the FDA completed a wave of inspections targeting about 30 compounding pharmacies with a history of complaints or problems. Inspectors reported finding a host of potential safety hazards, including rust and mold in supposedly sterile rooms.

Republicans charged that this “flurry of well-publicized activity” only proves that FDA has the ability to shut down pharmacies like the NECC.