A league spokesperson told FOX 5 that the investigation was prompted by what she described as a "credible press report."
Burke resigned from his coaching position on Tuesday, and was re-assigned to a front-office position in the organization.
In the meantime, he’s been placed on leave, pending an investigation into his behavior.
Wednesday morning, the Washington Post published a report citing three players who say they quit the team because of Burke’s "abusive" treatment.
The report documents instances in which players were yelled – sometimes within inches of their faces. In addition, the Post says players told them Burke hurled curse words and personal attacks at them.