Fox News contributor James Pinkerton confirmed that he was paid to “partner” with Michele Bachmann on her new book, but said he did not disclose his role in the project at the request of Bachmann and her publisher.

Pinkerton also revealed that Fox News knew of his arrangement from the start and approved of his keeping it from viewers.

“I was bound by a confidentiality agreement. They said, 'Don't tell anybody,' I said, 'Okay.' I told my superiors at Fox and they knew,” Pinkerton said Monday. “I helped on the book from June, July and August, I helped, in a collaborator sense. ... I helped as a collaborator to her. She was busy on the road, so she would have thoughts and tell me things and I would try and help put them together.”

Pinkerton is a regular panelist on Fox News' media criticism show and has frequently discussed Bachmann and the other presidential candidates.

Fox News did not immediately respond to a request for comment.

Pinkerton's role in the book first came to light Monday in a Politico story by Ben Smith that stated:

Michele Bachmann hired former speechwriter and domestic policy adviser to the first President Bush and to President Reagan, Jim Pinkerton, to help write her forthcoming memoir, “Core of Conviction,” POLITICO has learned.

Contacted by Media Matters Monday evening, Pinkerton confirmed he had collaborated on the book, saying he is mentioned in acknowledgements as “research and writing partner.”

Pinkerton said he had “zero regrets” about keeping his part in the book secret from Fox viewers, saying he always disclosed that his wife, a former Bachmann campaign chief of staff, was working for Bachmann.

“I chose not to [disclose his part in the book] because I wanted to protect the confidentiality of the book, although I told my [Fox] superiors,” he said. “Every time Bachmann came up, I said that my wife was working for the campaign, and I was making it clear that I had an interest, as it were, in the Bachmann campaign, through my wife's work.”

Asked why he did not disclose his book connection, Pinkerton said: “I felt that, I felt the need to keep the book confidential at the request of all parties involved.”

Which parties?

“The publisher, the candidate, the campaign.”

Pinkerton said he was paid to collaborate on Bachmann's book, but would not disclose the amount.

Pinkerton said he told Fox News “superiors” about his connection to the book in June. He declined to identify the superiors.

“I am a commentator, my views are well-known. I have been on Fox for 15 years, I've got lots of opinions on lots of things,” he added. “Any time that I mentioned Bachmann, I mentioned that my wife was working with Bachmann. The book is a different project not connected to Fox.”

He later sought to point out: “I am a contributor, and contributors are in a different category than full-time employees on Fox.”

Are you still involved in the book?

“No, book's done. My part was done, finished including edits and everything in early September.

”Let me make clear, I am a fan of Michele Bachmann, but I am not involved in her campaign and neither is my wife, at present."