Hollywood movie producers would kill for the kind of buzz that surrounds the barely seen video that could be the next bombshell in the campaign for the Republican presidential nomination.

The 27-minute video, produced by a political action committee that supports Newt Gingrich, attacks frontrunner Mitt Romney as a greedy destroyer of jobs during his time as the head of Bain Capital, a private equity firm.

At least, that's what the video is supposed to show. All that's been released is a three-minute trailer, now appearing on YouTube.

The group behind the video, Winning Our Future, plans to spend $3.4 million advertising in South Carolina before the Jan. 21 primary there, according to source familiar with the organization's advertising buys.

The ad bashing Romney is essentially an answer to one attacking Gingrich that was produced by a pro-Romney group and is widely credited with hammering Gingrich's standing in public opinion polls.

South Carolina's primary is crucial because it could be the last chance for conservatives such as Gingrich, a former House speaker, to keep Romney from sailing to the Republican nomination.

The anti-Romney ad, called When Mitt Romney Came to Town, accuses Romney, a former Massachusetts governor, and his former colleagues of profiting at the expense of workers' jobs.

Their greed was only matched by their willingness to do anything. Nothing was spared. Nothing mattered but greed, a narrator says in the trailer for the ad.

Thanks to a recent Supreme Court ruling, political action committees like Winning Our Future are able to accept unlimited contributions from donors.

The groups are legally separate from the candidates, and can be used to attack a candidates' foes without the favored candidate getting involved.

The anti-Romney film was directed by Jason Killian Meath, who made campaign ads for Romney in 2004. It was produced by Barry Bennett, a conservative activist who had shopped the film to at least one other PAC before Winning Our Future acquired it.

Until a few months ago, Bennett had been a consultant to Make Us Great Again, a PAC supporting Texas Gov. Rick Perry. Bennett showed part of the film to the group's leadership, which decided not to use the documentary, according to a source familiar with the PAC.

Make Us Great Again had nothing to do with this video in any way, Scott Rials, the group's executive director, said in a statement.

BIG SPENDING IN SOUTH CAROLINA

In recent days, Romney's opponents have seized on the governor's former business career, which he has made the centerpiece of his campaign.

The Romney campaign has fired back, arguing Gingrich and others are attacking free enterprise and parroting liberal Democrats.

The PAC supporting Romney, Restore Our Future, told The New York Times on Monday that it will spend $2.3 million in advertising in South Carolina promoting Romney.

The trailer of the anti-Romney ad utilizes a traditional liberal attack line, accusing Romney and his former company of outsourcing American manufacturing jobs to Asia and Latin America.

Unlike New Hampshire and Iowa, the first two primary voting states, South Carolina has been hit hard by the recession. Unemployment in the Palmetto State is 9.9 percent, above the national average of 8.5 percent.

Bennett, the film's producer, told radio interviewer Stephen K. Banon this weekend that he made the film because he knew that Democratic President Barack Obama campaign would seize on the material if he did not.

Last summer I started getting opposition books from the 2008 campaign, Bennett said, referring to the research that candidates compile against their opponents. I gathered three or four of the campaigns' books on Romney.

I said to myself right then, if I have these, I have to assume that (Obama's chief political adviser) David Axelrod has them too. If this guy (Romney) gets nominated, they are just going to kill him in the fall, Bennett said.

That the Gingrich campaign is relying on a PAC to keep his campaign afloat is not without irony. Gingrich has spent much of his time on the campaign trail decrying attacks aimed at him by the pro-Romney group.

These are the weapons of war, said Rick Tyler, a senior adviser to the pro-Gingrich group. These are the weapons that have been issued. I'm not going to unilaterally withdraw my weapon because I don't like the gauge my opponent has.

(Additional reporting Kristina Cooke in New York and Steve Holland in New Hampshire; Editing by David Lindsey and Cynthia Osterman)