Fox turned to undisclosed Mitt Romney supporter Ken Blackwell to attack President Obama's efforts to gain the support of women voters in Ohio.

Fox has allowed many of its contributors and guests to advocate for Romney and Republican election efforts without disclosing their ties to the campaigns or affiliated groups.

In the latest example, Fox & Friends co-host Gretchen Carlson interviewed Blackwell, a former Republican Ohio Secretary of State. Blackwell claimed that the presidential race in Ohio had narrowed because Romney had closed “a tremendous gap that existed with women.”

But Fox did not disclose that Blackwell is the chair of the Tea Party Victory Fund, an organization that has spent more than $144,000 to help Romney win the presidential election - even though Fox previously identified Blackwell as affiliated with another pro-Republican super PAC.

In August, Neil Cavuto hosted Blackwell on his Fox show Your World to promote an offshoot of the Tea Party Victory Fund, Defend Paul Ryan PAC. Blackwell described the organization's purpose as “making sure that the opposition and Obama forces don`t define, distort, and destroy Paul Ryan`s record and his chances of becoming, you know, Romney`s vice president.”

During his Fox & Friends appearance, Blackwell dismissed the Republican Party's efforts at the state and federal level to restrict women's reproductive health choices. He claimed  that the Obama campaign  “overplayed their hand in thinking that women were only concerned about abortion rights and contraception when many women in Ohio are worried about jobs and the education of their children.”