FRANKFORT — A Kentucky man pleaded guilty Friday to making illegal campaign contributions to candidates in last year’s governor’s race, including former Gov. Ernie Fletcher who was defeated in his re-election bid.

The case against Phillip Dufour, an employee of state road contractor Elmo Greer & Sons of London, was resolved by an agreement that required him to pay a $10,000 fine. In addition, Elmo Greer and Sons agreed to pay $250,000 to cover the cost of the investigation.

The agreement also requires the company to cooperate in further investigations by providing names of others who may have been involved, Attorney General Greg Stumbo said.

“Protecting our political process is essential to freedom,” Stumbo said in a statement. “With this criminal plea and significant fine, we have fired a shot across the bow of all who seek to taint elections with illegal contributions.”

Dufour entered his guilty plea to the felony charge in Franklin County Circuit Court. Dufour and his attorney didn’t immediately return calls seeking comment.

Prosecutors alleged that between Sept. 18, 2006 and Aug. 27, 2007, Dufour made improper payments to eight people who in turn made contributions to the Republican gubernatorial campaigns of Fletcher and former U.S. Rep. Anne Northup of Louisville and to the Democratic campaign of former Lt. Gov. Steve Henry of Louisville.

“We had absolutely no clue that that kind of activity was going on,” Henry said by phone Friday.

Henry said he couldn’t recall ever meeting Dufour and “certainly didn’t solicit any campaign contributions” from him, “and to my knowledge my campaign didn’t do it.”

Northup did not immediately return a call for comment. Jason Keller, who served as Fletcher’s spokesman during the campaign, said he was unaware of the attorney general’s latest investigation.

“Certainly the Fletcher campaign didn’t knowingly take any inappropriate contributions,” Keller said. “We will also refund any contributions found to be illegal.”

The investigation was sparked by a story last year in The (Louisville) Courier-Journal, which identified suspicious donations of up to $1,000 to gubernatorial candidates from people working in low-paying hourly jobs.

Kentucky has a long history of election fraud. In other cases in recent years, people have been accused of paying cash, even trading whiskey, for votes.

In late November, four eastern Kentucky officials were arrested on election fraud charges for allegedly trading government-owned gravel, asphalt and bridge-building materials for votes in a local election last year.

Knott County Judge-Executive Randall Clinton Thompson, Deputy Judge-Executives John Mac Combs and Phillip G. Champion and former county Magistrate Ronnie Adams were accused in a federal indictment of misappropriating public funds to influence the outcome of the general election on Nov. 7, 2006. They entered not guilty pleas.

The previous Knott County judge-executive, Donnie Newsome, served 16 months in federal prison after being convicted of election fraud in 2003.

Federal prosecutors have also pursued cases in a number of other Appalachian communities, the latest of which was Bath County.

More than a dozen people were charged in an alleged scheme there to pay impoverished residents to vote for particular candidates. Among those charged were candidates for judge-executive, county attorney and sheriff, all of whom were either convicted or pleaded guilty.

The lead prosecutor in the latest vote fraud investigation, Scott Crawford-Sutherland, declined to say if he expects more people to be charged. However, he said the investigation is ongoing.

“It sends a strong message to people who would skirt campaign finance laws,” he said.

Associated Press writer Bruce Schreiner in Louisville contributed to this report.