Sen. Scott Brown (R-Mass.) released a TV ad Monday that draws attention to Democrat Elizabeth Warren's claim to Native American heritage, shining a renewed spotlight on an issue that dominated local coverage of the campaign in the spring.

The ad, titled "Who Knows," consists entirely of clips of television reports on the subject of Warren facing questions about her claim to Native American heritage. "Elizabeth Warren is trying to put questions about her heritage behind her," says the newscaster in one of the clips. 

Warren listed herself as a minority in a faculty directory and told universities that employed her she was Native American. Brown has called on Warren  to release personnel records to prove she did not get an advantage as a result of her claim that she is a minority. Warren has said she gained no advantage because of her background. 

Last week, Brown signaled his intention to bring Warren's claim to Native American heritage to the forefront of the campaign discussion once again, when the senator brought up the issue in the opening minutes of his first debate against the Democrat. 

”Professor Warren claimed she was a Native American, a person of color — and as you can see, she is not,” Brown said at the debate. Brown's campaign has seized on Warren's inability to document her heritage claim. 

”I didn’t get an advantage because of my background," rebutted Warren.

Polling conducted in the spring after about a month of widespread coverage of the issue showed that Warren was largely undamaged by the back-and-forth. But it distracted from her ability to get her own message out.

Brown's new ad is his most aggressive of the campaign. He has mainly been running feel-good commercials that cast him as an every-man who still drives around in the pickup truck that became a symbol during his 2010 special election upset win. 

Warren released her most aggressive ad of the campaign 11 days ago. That spot argued Brown "has been siding with the big money guys."

Warren and Brown signed a pact earlier this year that levels fines against one another when allied outside groups run paid ads on their behalf. As a result, the super PACs that have been major players in other Senate races have stayed away, freeing Brown and Warren to be the main conduits of communication over the airwaves. 

Updated at 10:03 a.m.