The government's new consumer-watchdog agency is launching a probe into costly overdraft fees charged by big banks.

The Consumer Financial Protection Bureau says that it will ask banks for information about how the fees affect consumers, how overdraft protection is marketed and what information consumers receive.

The probe could result in new rules or even lawsuits if banks are accused of violating consumer laws.

The fees function like extremely high-cost, short-term loans. The agency says the cost of pushing your checking account into the red averages $30 to $35 per transaction.