Defenders of Wildlife, an independent environmental organization, is back on the airwaves this week with new ads attacking U.S. Rep. Marilyn Musgrave.

The 501(c)4 group is already airing a radio ad hitting Musgrave for, among other things, "giv(ing) billions in tax breaks to Big Oil" and co-sponsoring a bill that would benefit her coin-collecting husband by reducing capital-gains taxes on coins and precious metals.

A TV ad hitting Musgrave on her energy policy and the capital-gains tax issue will begin airing in the next few days, said Defenders of Wildlife spokesperson David Kirk. The ad is already up on YouTube.

Both of the new ads also repeat a claim made in an earlier anti-Musgrave Defenders ad that Musgrave was voted one of the most corrupt members of Congress. Media analyses of the earlier ad by CBS4 and 9News found that claim to be misleading.

Kirk declined to provide details of where the new ads are running as well as the size of the ad buys, citing organization policy.

Defenders of Wildlife made a six-figure ad buy against Musgrave over the summer.

Defenders, which played a key role in ousting former U.S. Rep. Richard Pombo (R-Calif.) in 2006, has turned Musgrave into a top target this cycle. This summer, Defenders dispatched Ed Yoon, who ran the organizations effort to unseat Pombo, to run field operations in its Musgrave campaign.

Musgrave's campaign did not immediately return a request for comment late Tuesday afternoon.