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John Edwards and his wife say they don't believe there was any financial wrongdoing.

WASHINGTON (CNN) - While acknowledging federal authorities are investigating the finances related to John Edwards political efforts, he and his wife say they don't believe there was any financial wrongdoing.

Investigators are focusing their inquiry on the more than $114,000 in payments from July 2006 through February 2007 by Edwards' political action committee to a production company owned by Rielle Hunter, a woman he had an affair with, according to the Raleigh News & Observer.

Hunter recorded web videos of Edwards for the political action committee. The payments were listed in federal election records as related to website/internet services work.

After months of tabloid rumors, Edwards admitted last summer he and Hunter had a previous affair.

In a statement given to several news organizations, including CNN, Edwards for the first time acknowledgedthere is an ongoing federal probe but would provide no further details.

"I am confident that no funds from my campaign were used improperly," Edwards said in the statement. "However, I know that it is the role of government to ensure that this is true. We have made available to the UnitedStates both the people and the information necessary to help get the issue resolved efficiently and in atimely manner."

Edwards' wife, Elizabth, told CNN Monday "there won't be anything that sticks on this."

A spokesman for the U.S. Attorney's Office in North Carolina refused to confirm or deny an investigation is ongoing.

Knowingly using money from a political committee for personal use is a federal crime.

In an interview with ABC's Nightline last August, Edwards said: "I've never paid a dime of money to any of the people that are involved. I've never asked anybody to pay a dime of money, never been told that money'sbeen paid."

Fred Baron, an Edwards financial backer, last year admitted paying money to Hunter and a man who claimed he was the father of her child. Baron died last year. Those payments would not be illegal.

"I decided independently to help two friends and former colleagues rebuild their lives when harassment by supermarket tabloids made it impossible for them to move forward on their own. I did this of my own volition without the instruction or suggestion of anyone, and made a concious decision not to tell anyone, including John Edwards, that assistance was provided. The assistance was offered and accepted without condition. This is now and shall always remain a private matter between these individuals and me," Baron said in a statement last August.

All of this comes as Elizabeth Edwards, suffering from another bout with cancer, is set to release her book, Resilience, later this week. In it she talks about how she learned of the affair and said at that point she "cried and screamed. I went to the bathroom and threw up," according to an advanced copy obtained by The New York Daily News. Elizabeth Edwards is scheduled to do a media tour after the release promoting it, and her husband's affair and how she has dealt with is expected to be a major topic of the interviews.

CNN Producers Dugald McConnell and Kevin Bohn contributed to this story.