NEW YORK (AP) — The U.S. Justice Department is investigating the Abbott Laboratories infant formula plant in Michigan that was shut down for months last year due to contamination, the company confirmed.

The factory's closure in February 2022 was a key cause of a nationwide baby formula shortage that forced parents to seek formula from food banks, friends and doctor's offices. Production restarted in June.

The Justice Department has informed Abbott of its investigation and the company is "cooperating fully," Abbott spokesperson Scott Stoffel said via email. He declined to provide further detail...