Federal prosecutors, working with securities regulators, are conducting a preliminary criminal probe into whether several major Wall Street banks misled investors about their roles in mortgage-bond deals, according to a person familiar with the matter.

The banks under early-stage criminal scrutiny-JP Morgan, Citigroup, Deutsche Bank and UBS-have also received civil subpoenas from the Securities and Exchange Commission as part of a sweeping investigation of banks' selling and trading of mortgage-related deals, the person says. Under similar preliminary criminal scrutiny are Goldman Sachs and Morgan Stanley, as previously reported by The Wall Street Journal.