The former director of quality assurance at Magellan Diagnostics conspired with executives to conceal a critical flaw in lead tests they knew would result in tens of thousands of false negative tests among lead-exposed children, according to the Department of Justice (DOJ).

Reba Daoust, former Magellan director of quality assurance and regulatory affairs; Amy Winslow, former chief executive officer; and Hossein Maleknia, former chief operating officer, repeatedly misled health clinics and the Food and Drug Administration (FDA) about the accuracy of lead-testing devices made by market leader Magellan, according to a grand jury indictment filed April 4 in U.S. District Court for the District of Massachusetts.

Children are considered lead exposed if blood tests show lead above a certain level. Some of the Magellan tests, including LeadCare Ultra and LeadCare II, included a flaw so they inaccurately showed low or no lead levels among children who potentially had lead levels above acceptable limits.

A high lead result tells doctors and parents to look for the source of lead, whether paint or toys, and remove it. Without that information, thousands of children continued to be exposed to lead, the DOJ said in a press release.

Daoust, Winslow, and Maleknia learned from internal testing the lead tests were not functioning properly while Magellan was seeking FDA approval in 2013 to begin selling the LeadCare Ultra tests, the DOJ alleged. Magellan ignored the problems, hid the information from the FDA, and started selling the test in December 2013, the DOJ said.

Hospitals allegedly soon noticed the tests were not detecting high lead in exposed children, and they complained to Magellan. Magellan replied to the complaints by falsely stating the company’s tests didn’t show any malfunctions, the DOJ said. Winslow and Maleknia allegedly directed a Magellan employee to stop studying a malfunction found in LeadCare II.

Daoust, Winslow, and Maleknia kept the information about the poor performance of the tests secret from the FDA and the public until the company was sold to Meridian Bioscience in 2016 and after a consultant who found out threatened to tell the FDA, the DOJ alleged.

When the FDA began its inquiry about the tests in 2017, Daoust and Maleknia directed those at the company responding to tell the agency Magellan only learned of the problem after the devices were on the market, the DOJ alleged.

Daoust, Winslow, and Maleknia were charged with conspiracy to commit wire fraud, wire fraud, conspiracy to defraud an agency of the United States, and introduction of misbranded medical devices into interstate commerce with intent to defraud and mislead. They potentially face more than 20 years in prison and fines beyond $250,000.

Magellan didn’t respond to a request for comment.