Republican leaders from the House Energy and Commerce Committee have asked the FDA to provide all documents related to the agency’s criminal investigations into the heparin contamination crisis.

Reps. Greg Walden (R-Ore.), Joe Barton (R-Tex.), Tim Murphy (R-Pa.) and Michael Burgess (R-Tex.) have requested additional information from the agency’s investigations into the heparin contamination crisis that killed at least 81 people and infected hundreds in 2008.

The documents are expected to provide the committee with further insights into the crisis and allow Congress to determine whether it needs to address any other issue to help the FDA take enforce regulations on drug adulteration.

Last year, the House committee pressed the FDA on the agency’s handling of drug adulteration and cited the heparin crisis as an example of the agency’s failure to identify economic adulteration prior to an outbreak and coordinate solutions to address these problems. The heparin crisis stemmed from Chinese manufacturers introducing a contaminant into the raw batches of the blood thinner to cut production costs.