Americans For Prosperity, the conservative political advocacy group tied to billionaire industrialists Charles and David Koch, and other Koch affiliates have spent more than $44 million on political activities in Wisconsin since 2010, according to liberal super PAC American Bridge.

American Bridge released the report on AFP's activities on Wednesday, two days before Americans For Prosperity is scheduled to open its fourth Wisconsin field office.

The new office will be located in Delafield. The organization already has operations running in Sheboygan, Wauwatosa, and La Crosse.

Americans For Prosperity's political activities in Wisconsin have included lobbying for the state's right-to-work law and rollback of the prevailing wage. The organization has also supported the political campaigns of leading state Republicans including Gov. Scott Walker, House Speaker Paul Ryan and U.S. Sen. Ron Johnson.

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According to American Bridge, which has financed ads against Johnson and the governor, the group’s political agenda is motivated by self-interest in Koch Industries' profits.

"There is an agenda at play here," said Eddie Vale, vice president at American Bridge. "They are not doing this to be altruistic, they're doing it because they have a self-interested agenda in making more money for Koch Industries.”

A spokesperson for Americans for Prosperity didn't return repeated requests for comment on Wednesday.