WASHINGTON - U.S. auto safety regulators said on Tuesday they are investigating if Hertz rented unrepaired recalled vehicles to customers.

The National Highway Traffic Safety Administration said in a filing made public on Tuesday it was in receipt of information that indicates "Hertz rented vehicles to customers without having performed required recall repairs".

The agency said it had opened an "audit query to seek additional information concerning this issue".

The agency said the issue involved Ford Explorer and Nissan Altima cars but did not disclose the number of vehicles involved.

(Reporting by David Shepardson, editing by Ed Osmond)