(NewsNation) — The Justice Department is investigating Abbott Laboratories over a plant shutdown that resulted in a major infant formula shortage last year, the company confirmed.

Parents across the country were left scrambling to find formula on barren store shelves after the Sturgis, Michigan, manufacturing halted operations in February 2022 when federal inspectors found a potentially deadly bacteria there. The height of the shortage hit in late spring — by the end of May 2022, shortages spiked to over 74%, according to data tracked by Datasembly.

Attorneys with the DOJ’s consumer-protection branch are conducting the investigation, the Wall Street Journal first reported. That branch was involved last year in a settlement with Abbott that allowed the Sturgis plant to continue operations after the FDA found the bacteria.

“DOJ has informed us of its investigation and we’re cooperating fully,” an Abbott company spokesperson said.

Abbott closed the Michigan plant in February 2022 and recalled its products following reports of bacterial infections in four infants, two of which died. This closure was center to the nationwide baby formula shortage.

The Biden administration began flying in formula from overseas to address the shortage, which some parents are still feeling the effects of nearly a year later. The plant restarted production of its Similac formula in August.

Federal investigators could not conclusively link the bacteria found in the formula to the Michigan plant, and Abbott said genetic sequencing of bacteria found in sick babies didn’t match the strains found at the plant, the Wall Street Journal reported.

Abbott issued another recall in October, this time for poorly sealed bottle caps. The company said at the time it would not impact the nationwide supply.