The former chair of the Republican Party of Florida has been cleared of a high-profile accusation of rape, but could still face a voyeurism charge.
Christian Ziegler is accused of recording a sex act without consent, police said in a statement on Thursday.
A woman with whom he and his wife had a prior consensual sexual relationship previously alleged that he raped her.
Earlier this month, Florida Republicans overwhelmingly voted to remove Mr Ziegler, 40, as their party leader.
According to heavily redacted police documents, Mr Ziegler, his wife, Bridget Ziegler and the unnamed woman had planned a threesome in October, but Mrs Ziegler was unable to attend.
Mr Ziegler instead arrived alone, the complaint alleged, and assaulted the woman.
But police in Sarasota say they reviewed hours of video evidence and conducted nearly a dozen interviews and determined that it was unlikely that any sexual battery took place during the 4 October encounter.
"Ziegler recorded the encounter on his cell phone," Sarasota Police Department said in the Thursday statement.
"The video showed that the encounter was likely consensual. Therefore, detectives were unable to develop probable cause to charge Ziegler with Sexual Battery."
But the statement added that Mr Ziegler could still face felony charges of video voyeurism, a crime punishable by five years in prison and a $5,000 ($3,935) fine.
"The victim advised Sarasota Police detectives that she was unaware and did not consent to being video recorded," the statement said, adding that the charge would be submitted State Attorney's Office for further review.
Derek Byrd, a lawyer for Mr Ziegler, said in a statement that "since day one, we have been confident Mr Ziegler would be exonerated from these baseless allegations".
He added that he believed Mr Ziegler will ultimately never face any charges.
A police spokeswoman told the Daily Beast that the rape investigation is continuing and "is still active at this time".
The ongoing saga has brought a rapid fall from grace for the Zieglers, a conservative Florida power couple with growing political influence on the national stage.
Bridget Ziegler, an elected member of the Sarasota County School Board, is co-founder of Moms for Liberty, a national right-wing advocacy group born out of a resistance to Covid-19 school closures and mask mandates.
She has resisted calls to resign, fielding criticism from many who cast Mrs Ziegler - who with her husband has promoted anti-LGBT policies - as a hypocrite.
