A prominent South Carolina lawmaker has accused Governor Mark Sanford of a smear campaign against Lieutenant Governor Andre Bauer. State Senator Jake Knotts says Sanford and his supporters are behind a rumor that Bauer is gay.

Knotts, a Republican, is an outspoken critic of the governor.

“As a former target of a false rumor started by the Sanford Camp I can tell you with absolute certainty this attack was orchestrated on behalf of Mark Sanford, either directly or indirectly, and finally subsidized by him or one of his many 'front-groups',” Knotts said Wednesday in a letter distributed to South Carolina lawmakers.

Gay rumors have dogged Bauer for years, but on Monday activist blogger Mike Rogers, who claims a perfect outing record, called Bauer “a closeted anti-gay politician” in a blog post at blogactive.com. Bauer, who assumed office in 2003 after serving in both chambers of the Legislature, often appears alongside of anti-gay former presidential candidate Mike Huckabee.

Sanford, a Republican, continues to resist calls to step down over an embarrassing sex scandal. Last week, Bauer, who is next in line for the governor's mansion, joined the chorus of elected officials calling for Sanford's resignation. Knotts called the rumor's timing into question, saying it is “obviously not a coincidence.”

In an interview with CNN, Knotts vouched for Bauer's heterosexuality: “I have known Andre since he was eight years old. Ain't a homosexual bone in his body. That boy is a good boy. It's just an attempt to prevent Andre from becoming governor.”

“Every time I have seen Andre and as long as I've known him, he's always had a pretty girlfriend. They love him, he treats them well, he treats them nice, he treats them with respect. He doesn't hang out in bars and go from woman to woman. Everybody that knows Andre knows for sure he ain't been seen hanging on to no damn man,” the senator added.

Sanford has denied Knotts' allegations.

“This letter is simply wrong – and in that regard, as bizarre as many of the other claims and attacks of recent weeks,” said Sanford spokesman Ben Fox. “Some have argued this indeed points to an obsession with slandering anyone who tries to change the 'good ol' boy' system of politics in Columbia.”

Knotts played a central role in drawing national attention to Sanford's mysterious disappearance in June, before it was known that he had left the country to be with his Argentinian mistress, and in his letter urged lawmakers to impeach Sanford.

“We cannot allow this type of groundless, baseless, Internet slander against public officials to continue to exist in our state. The Legislature now has the opportunity to look into ending it once and for all. If we don't you and your family could be the next target,” Knotts said.