Speaking with reporters, Brown was asked about a report on WCVB-TV, Boston, that members of his staff used the stereotypical gestures to mock Warren at a campaign rally Saturday. WCVB reported Brown's deputy chief of staff, Greg Casey, and another staffer, Jack Richard, along with Brad Garrett, identified as a Republican Party operative, are shown using the gestures in a video posted online by the liberal Blue Mass Group.
Brown has raised the issue of Warren's ethnicity, suggesting she falsely claimed to be part American Indian to advance her career.
He told reporters Tuesday he was not aware of the video involving his staffers but "certainly that's not something I condone."
"It's certainly something that if I am aware of it, I'll tell that [staff] member to never do it again," Brown said in an audio clip provided by his campaign. "But the real issue here is, and the real offense is the fact that Professor Warren checked the box. She said that she was white, and then she checked the box saying she was Native American and then she changed her profile in the law directory once she attained her tenure. That's quite offensive to Native Americans."
Warren's employers have said her ethnicity was not a factor in her hiring but Warren has rejected Brown's demand that she release her employment records, Politico reported.
Warren spokeswoman Julie Edwards said the video showing Brown staffers using "war whoops" and tomahawk chops is "clearly inappropriate and offensive behavior, particularly from Senate staff."
Brown raised the issue of Warren's ethnicity during a candidates' debate last week as polls in Massachusetts show her pulling ahead. He then started running ads criticizing her for claiming she is part American Indian.
Warren responded with an ad that says: "Scott Brown can keep attacking my family, but I'm going to keep fighting for yours," Politico reported.