The Department of Transportation on Tuesday demanded that Toyota turn over documents proving "the automaker conducted three of its recent recalls in a timely manner."

Under federal law, car manufacturers must notify the National Highway Traffic Safety Administration (NHTSA) about a vehicle model's safety defect within five days of discovering the flaw, according to the department.


But NHTSA officials signaled Tuesday they are unsure whether Toyota complied with that rule. Consequently, they implored the manufacturer to release documents showing how and when company executives first discovered problems that have so far prompted Toyota to recall more than 6 million vehicles.

Toyota has at least 30 days to comply with the order, according to reports. It could face stiff penalties, including fines, if it opts not to turn over its records.

"Safety recalls are very serious matters and automakers are required to quickly report defects," Transportation Secretary Ray LaHood said in a statement.

"Our top priority is safety and we expect that all manufacturers address automotive safety issues quickly and in a forthright manner," added David Strickland, administrator for the NHTSA.

The department's announcement on Tuesday arrives in response to the public's unprecedented criticism of Toyota, which has recalled millions of cars this year because of potentially life-threatening defects -- from sticking gas pedals, to latency in some cars' brake controls. Ultimately, Toyota could face up to $16.4 million in civil penalties for some of those errors, according to NHTSA.

At the same time, a number of federal lawmakers are demanding additional action against the embattled car manufacturer. Some are even pining for the company's CEO, Akio Toyoda, to testify on Capitol Hill while he is in Washington for meetings next week, but it remains unclear whether Toyoda will comply.