The U.S. National Highway Traffic Safety Administration is investigating whether Graco Children Products waited too long to report a safety defect that it says affected nearly 4 million child car seats.
Graco, a subsidiary of Newell Rubbermaid, first reported the issue to NHTSA in February, describing it as a safety defect in the harness buckles, but said it had been monitoring the problem since 2009 and had provided some customers with replacement buckles.
The buckles could become stuck and create an "unreasonable risk" to a child's life in the event of an emergency, NHTSA said.
"Any delays by a manufacturer in meeting their obligations to report safety issues with the urgency they deserve, especially those that impact the well-being of our children, erodes that trust and is absolutely unacceptable," says Anthony Foxx, U.S. Transportation Secretary.
Graco recalled more than 6 million booster seats in the U.S. earlier this year, making it the biggest child-seat recall in the country's history.
The baby product manufacturer faces fines of up to $35 million in civil penalties if its found liable, the regulator said.
"We thoroughly analyzed all data related to the buckles and took the required actions to keep our consumers safe. We worked cooperatively with NHTSA throughout its investigation and will continue to do so moving forward," a Graco spokesperson told CNBC Monday. "The safety of our products and the consumers that use them is paramount and underlies every decision we make."