CBS News has learned that U.S. investigators are looking into whether Trump campaign representatives had a role in helping Russian intelligence as it carried out cyberattacks on the Democratic National Committee and other political targets in March 2016.

This new information suggests that the FBI is going back further than originally reported to determine the extent of possible coordination. Sources say investigators are probing whether an individual or individuals connected to the campaign intentionally or unwittingly helped the Russians breach Democratic Party targets.

In March 2016, both Mr. Trump and Hillary Clinton had emerged as their parties’ most likely nominees.

According to a declassified intelligence assessment, it was in March when Russian hackers “began cyber operations aimed at the U.S. election.” In May, U.S. officials say the Russians had stolen “large volumes of data from the DNC.”