Updated

Ron Paul categorically denied on Sunday allegations from Michele Bachmann that his campaign or someone tied to it offered her Iowa co-chairman money to join his team, and Paul challenged Bachmann to prove the charge.

"If she has the evidence, she should bring it forth, because if she makes charges like that, she should be able to defend it," Paul said on "Fox News Sunday." "But no, that did not happen."

Bachmann's campaign on Wednesday accused Paul of buying off Kent Sorenson, also a state senator, who bolted her campaign to endorse the Texas congressman in the race for president.

She said Sorenson told her he was offered money -- an allegation Sorenson has since denied.

However, Sorenson's former campaign manager has supported Bachmann's claim that he was offered money. Bachmann, on "Fox News Sunday," cited that in defending her original charge.

"This is pretty clear," Bachmann said.