Americans For Prosperity, the conservative group funded by the Koch brothers, is spending between $24 and $25 million on a month-long ad buy in 11 swing states, a Republican media buyer has confirmed.

RENO, NV - JULY 23: Former Republican presidential candidate Herman Cain speaks during an American For Prosperity rally on July 23, 2012 in Reno, Nevada. Hundreds of people attended an Americans For Prosperity rally to see former Republican presidential candidate speak. (Photo by Justin Sullivan/Getty Images) (Justin Sullivan/GETTY IMAGES)

The size of the new AFP buy was first reported by NBC News, which added that the ad will begin running next week and continue through the first week of September. Politico first reported the buy’s outline and the states in which the ads will run. A spokesman for AFP would not confirm the spending.

AFP, along with other Republican-aligned organizations like American Crossroads and its sister organization Crossroads GPS, have already been spending heavily on behalf of former Massachusetts governor Mitt Romney’s campaign.

Prior to this latest buy, AFP had already spent $17.6 million on ads in the presidential race. The Crossroads groups alone plan to spend $300 million on congressional races and the presidential race this cycle.