Updated

The former Michele Bachmann supporter who defected to the Ron Paul team this week said he was "never offered a nickel" by Paul's campaign, disputing the Minnesota congresswoman's claim that he was bought off.

Iowa state Sen. Kent Sorenson, who was a Bachmann Iowa co-chairman before he resigned Wednesday and endorsed Paul, accused Bachmann of fabricating a story about a conversation they had before he bolted. Bachmann had said in a radio interview Thursday that Sorsenson told her he was offered "a lot of money" by Paul's people.

"That's why he left," Bachmann said. She later repeated the claim in an interview on Fox News.

But Sorsenson told Fox News on Thursday "that conversation did not happen."

Asked if he was offered money to leave Bachmann, he said, "absolutely not." Rather, Sorenson cited past political support he received from Paul's people and said he jumped over to Paul to help him beat Mitt Romney at a critical time in the race.

"I gave (Bachmann) 110 percent. I believe we're at a time where Michele is not going to win Iowa," he said. "I decided that it was time to come to his aid and help put him over the top."

Sorsenson said it's "unfortunate" that Bachmann is making these claims, but said: "I did not accept any money from the Ron Paul campaign."

Bachmann and Sorenson, however, are adamant that their respective version of events is accurate. They've each brought out witnesses to back up their stories, in what has turned into an unusual campaign sideshow just days before the caucuses.

Bachmann first leveled the charge in a statement Wednesday, saying Sorenson was offered money to join the Paul camp.

"Kent Sorenson personally told me he was offered a large sum of money to go to work for the Paul campaign," Bachmann said in the statement. "Kent campaigned with us earlier this afternoon and went immediately afterward to a Ron Paul event and announced he is changing teams. Kent said to me yesterday that 'everyone sells out in Iowa, why shouldn't I?', then he told me he would stay with our campaign. The Ron Paul campaign has to answer for its actions."

Sorenson's former campaign manager Susan Geddes vouched for Bachmann's assertion that money was behind the move.

Geddes said on Fox News that Sorenson told her as early as March that Paul was offering him money to join the team.

Sorenson, though, flatly denied the charge. And Paul's campaign forwarded around a statement from a Bachmann campaign official saying Sorenson's decision "was in no way financially motivated."

"It was not the basis of his decision," Bachmann Iowa official Wes Enos said. Enos has since left the Bachmann campaign, according to a source.

Steve Deace, a friend of Sorenson, told Fox News that Sorenson has a long-standing relationship with Paul.

"The Paul people helped him, and really were the only ones who stood up for him in his two races," Deace said.

Fox News' Steve Brown contributed to this report.