FRAMINGHAM, Mass. (WHDH) -- Federal investigators were at the New England Compounding Center, the pharmacy linked to the meningitis outbreak, Tuesday.

Investigators blocked the entrance to the center. Agents went in and out of the facility for hours with no word on what they're learning.

Earlier in the day U.S. legislators voiced that they want the U.S. Department of Justice to investigate whether the company linked to the outbreak violated federal laws or regulations.

Mass. Rep. Edward Markey told the department in a letter that the NECC may have tried to skirt federal policy on the scale and distribution of controlled substances.

Rep. Markey told 7News over the phone, "The is a deadly, serious situation involving highly sensitive drugs and vulnerable patients which will demand the strongest response from the Justice Department, from the DEA, and from the United State Congress...We don't know whether this is the iceberg or the tip of the iceberg and a national wave of companies escaping federal regulations that ultimately could endanger public health and safety."

Tainted steroids from the NECC are connected to the outbreak that has sickened more than 200 people in 15 states and at least 15 people have died.