New York's attorney general is investigating six of the top U.S. banks over reports that they are unfairly using databases to disqualify people seeking to open checking or savings accounts, the New York Times reported on Thursday, citing people briefed on the matter.

Bank of America Corp (BAC.N), Citibank Inc (C.N) and JPMorgan Chase & Co (JPM.N) are among the banks that received letters from state Attorney General Eric Schneiderman, according to the newspaper. The banks have until Tuesday to schedule a meeting and discuss the matter with the agency.

Schneiderman's office did not immediately respond to a request by Reuters for comment. Citigroup declined comment, while JPMorgan and Bank of America were not immediately reachable. The newspaper did not identify the other three banks.

An increasing number of banks and credit unions are running stringent checks to guard themselves against risky customers and fraud. However, the databases on which these banks rely are disproportionately affecting lower-income Americans, according consumer advocates and state authorities, the newspaper said.

Negative reports in the databases have eliminated over a million lower-income Americans from the financial system and forced them towards using costly operations to pay bills or cash a check, the New York Times said, citing interviews with financial counselors, consumer lawyers and over two dozen low-income people in California, Illinois, Florida, New York and Washington.

The newspaper added that the prosecutor is mainly seeking information on the banks' use of databases to make sure consumers are not improperly denied or restricted banking access.

The databases could especially harm African-Americans, Latinos and other minority groups, the paper cited Schneiderman's office as saying.