Restore Our Future, the super PAC backing presumptive Republican presidential nominee Mitt Romney, spent more than $20 million on deceptive ads in early primary and caucus states, according to a just-released study by the Annenberg Public Policy Center. That figure includes more than $9 million in ads distorting the record of former House Speaker Newt Gingrich, who is set to endorse Romney on Wednesday.

Relying on the spending estimates of commercial ad-tracking company Kantar Media CMAG and the content analysis of Annenberg's own FactCheck.org, the center calculates that outside groups spent a total of $41.1 million through the April 3 Wisconsin primary on 19 ads that contained deceptive or misleading claims. Groups guilty of deception, according to the policy center, also included two super PACs backing Romney rivals -- the Red, White and Blue Fund, which supported former Sen. Rick Santorum and the pro-Gingrich Winning Our Future -- as well as the Democratic-leaning American Federation of State, County and Municipal Employees.

More than half the money the four groups spent on television ads went for spots that were misleading, the Annenberg study concluded. By the policy center's tally, Restore Our Future was by far the biggest offender, responsible for 89 percent of the campaign's deceptive dollars. So far, Restore Our Future has not returned Sunlight's call requesting comment.

The Annenberg list of deceptive ad claims includes some whoppers that may prove embarassing as Romney tries to mend fences with his former rivals. Particularly relevant given this week's anticipated lovefest between Romney and Gingrich: Winning Our Future's distortions of Romney's record on abortion and as a businessman and Restore Our Future's efforts to tie Gingrich to the "economic collapse" by exaggerating the terms of his contract with the quasi-governmental mortgage agency, Freddie Mac.

Kathleen Hall Jamieson, a University of Pennsylvania political scientist who directs the Annenberg Public Policy Center, is cataloguing deceptive advertising and calling on television stations to refuse to air advertisements that make misleading claims.