A tea party activist in Mississippi has been arrested in connection with the filming of Sen. Thad Cochran's bedridden wife, the latest twist in a story that has rocked the stretch run of the Republican primary for U.S. Senate in that state.

Sen. Thad Cochran (R-Miss.) (Bill Clark/CQ Roll Call)

Authorities on Thursday arrested Mark Mayfield, his attorney Merrida Coxwell told Post Politics in a brief interview. Mayfield is the vice chairman of the Mississippi Tea Party and a supporter of state Sen. Chris McDaniel, Cochran's GOP primary opponent.

The Madison Police Department said it also arrested two others in connection with the investigation: Richard Sager and John Mary, who was released due to an extensive medical condition.

The news comes on the heels of the arrest of blogger Clayton Thomas Kelly last Friday on allegations that he filmed Cochran's wife, Rose Cochran, in a nursing home and posted at least one image of her in an online video. Kelly has written items praising McDaniel and criticizing Cochran.

McDaniel and his campaign have denied any involvement in Kelly's alleged effort to film Rose Cochran, who suffers from dementia and has stayed at the nursing home since 2000. But Cochran's campaign has raised questions about whether McDaniel's team knows more than they've been acknowledging, citing the timing of remarks the McDaniel campaign has made.

Meanwhile, McDaniel has raised questions about why Cochran's campaign waited weeks after learning about the video before alerting authorities.

The entire episode has drowned out everything else in the campaign ahead of the June 3 primary.

In a statement Thursday, McDaniel said that anyone who violated the law must be held accountable.

"As we have said since day one, the violation of the privacy of Mrs. Cochran is out of bounds for politics and is reprehensible. Any individuals who were involved in this crime should be prosecuted to the fullest extent of the law," he said.

Cochran's campaign declined to comment on the Thursday arrests.

Updated at 7:59 p.m.