Federal Reserve Bank of San Francisco officials are investigating Wells Fargo & Co. concerning its guaranteed auto protection insurance, The New York Times reported Aug. 7, noting that tens of thousands of customers may have been affected.

In Wells Fargo's Form 10-Q, the bank disclosed that it "has identified certain issues related to the unused portion of guaranteed auto protection waiver or insurance agreements between the dealer and, by assignment, the lender, which may result in refunds to customers in certain states."

Spokeswoman Jennifer Temple told NYT that Wells Fargo found issues related to the administration of guaranteed asset protection products, but declined to disclose when the problem started.

Wells Fargo Dealer Services is the bank's unit that offers car loans, the report added.