(REUTERS) Kate Kielland, August 9, 2017 — The chairman of a congressional committee has asked the U.S. National Institutes of Health (NIH) to explain why its National Cancer Institute (NCI) failed to publish data that showed no links between glyphosate and cancer.

In a Tuesday letter seen by Reuters, U.S. Representative Trey Gowdy, who chairs the House Committee on Government and Oversight Reform (OGR), said he “is concerned about the new revelations” and is “seeking more information” about why the exculpatory results were not published by the NCI.

Glyphosate is a key ingredient in Monsanto’s top-selling weedkiller Roundup.

Gowdy’s letter to NIH Director Francis Collins follows a June report by Reuters which found that a senior scientist from the NCI knew that fresh data from a large research project known as the Agricultural Health Study (AHS) showed no links between glyphosate and cancer.

Draft scientific papers dating from 2013 containing the data were never published. Consequently, the information was not able to be taken into account during the March 2015 review of the pesticide by the World Health Organization’s International Agency for Research on Cancer (IARC).

An NIH spokeswoman told Reuters the NIH had received Gowdy’s letter “and will be responding directly to the committee.”

Aaron Blair, the senior scientist at the NCI who knew about the data and also chaired the IARC review, previously told Reuters the data was not published in time because there was too much to fit into one scientific paper. Blair is now retired from the NCI.

Source: U.S. lawmakers seek missing information in review of Monsanto weedkiller