A trio of edgy online videos attacking GOP presidential front-runners may comprise a new "dirty trick" in the 2008 presidential race — if anyone can figure out where they came from. One campaign and one consulting firm have denied purported links to the ads, which were posted to online video-sharing site YouTube.com and disseminated by a user of the MySpace.com social networking site in early July. The spots feature a fast-talking young man in glasses tossing off a series of over-the-top observations about the Republican primary candidates, while driving a car. Video Watch Excerpts of the Online Videos Slamming GOP Presidential Hopefuls "If you gotta stick a plunger up somebody’s ass to reduce crime, you stick a plunger up somebody’s ass," the man says in one spot, which appeared on the niche politics-and-sleaze-themed Wonkette.com blog. The comment is a reference to one of the darker moments of GOP White House hopeful Rudy Giuliani’s time as mayor of New York, the New York Police Department’s bloody beating of Abner Luima in 1997. The police had arrested the Haitian immigrant on charges of disorderly conduct and resisting arrest. At the time, Giuliani said the alleged abuse was "shocking" and "reprehensible." The ads end by fading to black, and the Web address for Giuliani’s campaign appears. The Giuliani campaign unsurprisingly denies any connection to the videos. In a July 11 letter, it asked YouTube to remove the videos, but the spots are still posted. YouTube did not respond to requests for comment. Click Here for Full Blotter Coverage. In other spots, the fast-talking driver makes more outrageous claims about GOP candidates. "Mitt Romney? Now that’s a good-looking man," he says in another. "Him and Fred Thompson, now that’s an attractive gay couple…They don’t call Fred Thompson ‘Hollywood Fred Thompson’ for nothing. And we all know what ‘Hollywood means," the man says, as upbeat music plays in the background. "That young hot wife they’re all talking about?" he asks rhetorically, apparently referring to Jeri Thompson, Fred’s wife. "Oh, yeah. Transgender." The ads "have nothing to do with us," Giuliani spokeswoman Maria Comella told the Blotter on ABCNews.com Tuesday. Photos Check Out Pictures of the Mysterious Online Videos Then who? The Daily Background blog noted the ads had been posted to several online forums by a MySpace account which appeared to belong to an employee of the Washington, D.C. political advertising firm Stevens, Reed, Curcio and Potholm. The firm gained prominence in 2004 by producing ads for the group "Swift Boat Veterans for Truth," attacking Democratic presidential candidate John Kerry for allegedly lying about his war record. The firm now works for Sen. John McCain’s presidential campaign. Executives there told ABCNews neither the firm nor its employee was involved in creating or disseminating the ads. "This is a complete fabrication and a hoax," firm partners Rick Reed, Paul Curcio and Erik Potholm told ABCNews.com in an e-mailed statement. "No one at SRCP was involved in the creation or production of these ads or the personal content created and posted on MySpace which is attributed to one of our employees." A campaign spokeswoman for McCain told ABCNews.com neither the candidate nor his team had any knowledge of the videos. The MySpace profile that appears to belong to a firm employee boasts 91 friends and belongs to several Republican discussion forums. On July 13, after a blogger noted apparent connections between the ads and the firm employee, someone with access to the profile commented on another MySpace user’s page, "Issues with the ‘campaign’ really heated up at work today; big time. I might have royally screwed something up. Though I could probably use a stiff drink, I don’t think I should go out in public much in the next few weeks." In a July 16 letter, the firm’s lawyer asked at least one blogger to cease his "false assertions" linking SRCP to the ads. The firm said the lawyer had sent copies of that letter to MySpace and the online video hosting service YouTube, where an account was created to host the spots under a name similar to the firm’s employee. The first two ads did not mention Sen. McCain, R-Ariz. In the latest ad, posted July 12, the driving star rolls out a rambling screed on the former prisoner of war. "Shot down in Korea? [He's a] Manchurian candidate," the driver surmises. "McCain was brainwashed by the Koreans, which could explain his flip-flopping on the whole immigration thing. …You notice the blemishes" — he gestures to his face — "they say it’s skin cancer? That"s not skin cancer. That"s the truth serum they injected into him." This is the second time an anonymously-created YouTube video has caused a stir in the 2008 presidential race. In March, a video portraying Sen. Hillary Clinton, D-N.Y., as an Orwellian dictator created a minor uproar. Once identified, the ad’s creator, Philip deVellis, was fired from his job at a media firm employed by the presidential campaign of Sen. Barack Obama, D-Ill. Both the Obama campaign and deVellis’ old firm, Blue State Digital, said the candidate and his campaign had no knowledge of the ad. MySpace.com did not respond to requests for comment on this story. As of Wednesday afternoon, the alleged "hoax" profile was still available on its site. This post has been updated. Do you have a tip for Brian Ross and the Investigative Team?