Federal prosecutors continue to pursue criminal charges against three top campaign advisers to 2012 presidential candidate Ron Paul.

In a new grand jury indictment filed Thursday in federal court in Des Moines, Paul's 2012 campaign chairman Jesse Benton, campaign manager John Tate and deputy manager Dimitri Kesari are charged with conspiracy to cover up $73,000 in campaign payments to former Iowa Sen. Kent Sorenson. Sorenson dropped his support for Michelle Bachmann and endorsed Paul in December 2011, six days before the Iowa caucuses.

Benton, Tate and Kesari also are charged with causing false campaign contribution reports to be filed to the Federal Election Commission and participating in a false statement scheme. Benton and Tate are charged with causing the campaign to file false records of the payments. Kesari was convicted of that charge last month.

The three men were originally charged in August, but a judge dismissed charges against Tate and all but one charge against Benton because they were based on information the government obtained during FBI interviews last year that the judge said was not admissible.

In the new indictment the charges are based primarily on emails and other communication the prosecutors plan to offer into evidence.

Benton was tried on one count of lying to the FBI, but a Des Moines jury acquitted him of that charge last month. At the same trial Kesari was convicted of causing the campaign to file false records but jurors said they could not reach a verdict on counts alleging conspiracy, causing false campaign expenditure reports and a scheme to falsify statements. Those charges are refiled against Kesari and Benton in the new indictment.

"Mr. Kesari maintains his full innocence in this matter and he looks forward to further vindicating himself before a jury of his peers," his attorney Jesse Binnall said.

Tate's attorney said his client is innocent "and looks forward to prevailing at trial so he can move forward with his life."

Benton's attorney said he was reviewing the new charges and may offer a statement later. He filed a not guilty plea on Friday.

The first court appearance for the three on the new charges is set for Dec. 2. Prosecutors filed a motion seeking a Feb. 8 trial.

The men have previously said they believe the prosecution is politically motivated and that they are another example of the federal government going after tea party-backed conservatives. They said Sorenson's job as a subcontractor is common in campaigns and the law doesn't require disclosure of payments to subcontractors.

In last month's trial Paul told jurors he suspected federal prosecutors unsealed the indictment against them one day before his son, Kentucky Sen. Rand Paul was set to appear at the Republican Party's first debate of the 2016 campaign.

"I don't consider that a coincidence," Ron Paul said.

Tate is the founder and president of America's Liberty, one of several super political action committees supporting Rand Paul's presidential campaign. Benton, who also helped lead the PAC, is married to Ron Paul's granddaughter, Valori Pyeatt, Rand Paul's niece. Tate and Benton took a leave of absence from the PAC when they were charged.

Sorenson, who entered a plea deal with the government on charges of obstruction of justice and causing a campaign to falsely report expenditures, testified for the prosecution at the first trial.