"It would be hard to see my brother as anything but a racist", Mr Gosar's sister Grace tells voters in another upcoming advert, according to The Phoenix New Times.
"Where is his integrity?" asked sis Jennifer Gosar in an ad she filmed for her brother's Democratic opponent, David Brill.
"None of this is pleasant for any of us", David Gosar says. "It's appalling. It's disgraceful", David Gosar said.
It opens with "Grace, rural physician", declaring, "Paul Gosar the congressman isn't doing anything to support rural America". "I'm not going to break bread with a racist".
Next up is "Jennifer, medical interpreter" who says "If he actually cared about people in rural Arizona, I bet he'd be fighting for social security, for better access to healthcare".
That upset Nancy Bryce, their mother, who has denounced the campaign ad in a letter that was recently made public.
David Gosar suggested to the New Times that his brother's health may be deteriorating.
Gosar also made headlines earlier this year when he called on police and Attorney General Jeff Sessions to check the immigration status of protesters attending President Donald Trump's State of the Union address in January.
The next month, Gosar said FBI and Department of Justice officials such as Deputy Attorney General Rod Rosenstein, former acting Attorney General Sally Yates, and former FBI Director James Comey should face "treason" charges due to developments in the Russian Federation investigation. Gosar also flew to London to speak at an anti-Muslim rally, with his travel funded by the anti-Muslim Middle East Forum group.
In it, six men and women discuss their various problems with Gosar as a candidate - before revealing that they're all his siblings. "Those aren't our family values or the values of the small Wyoming town we grew up in". Brother Pete, who ran for governor of Wyoming in 2014 as a Democrat, does not appear in the ads.
In total, Gosar nine siblings. After Charlottesville they said they barely recognize their brother.
Lawyer David adds: "He's not listening to you, he doesn't have your interests at heart".