(Reuters) - The man accused of tackling U.S. Senator Rand Paul of Kentucky and breaking his ribs as he was mowing his lawn pleaded not guilty on Thursday to a misdemeanor assault charge, a court official said.

Rene Boucher, 59, waived the formal reading of the charge at a hearing in Bowling Green, Kentucky, Warren County Attorney Amy Milliken said by telephone.

Boucher, the Republican senator’s neighbor, is charged with fourth-degree assault causing minor injury, for which he faces up to a year in jail if convicted. A pretrial hearing was set for Nov. 30.

Paul, 54, told police that Boucher came onto his property in a gated community near Bowling Green and tackled him from behind, the Bowling Green Daily News reported, citing an arrest warrant.

Paul said on Twitter on Wednesday that he suffered six broken ribs and that X-rays showed a pleural effusion, which is a buildup of fluid in the tissues that line the lungs and the chest.

The Kentucky State Police and the Federal Bureau of Investigation are investigating last Friday’s incident, Milliken said.

Citing unnamed sources, Fox News reported on Thursday that Paul had been told federal charges were expected in the case. The senator’s office did not immediately reply to a request for comment on that possibility.

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Matt Baker, Boucher’s attorney, was not immediately available to comment.

Baker told Bowling Green television station WBKO that the incident was related to a property dispute and called the idea that Paul was “blindsided” an unfair characterization. Baker also told the TV station that politics was not a motivating factor in the dispute.

Media reports have said Boucher, also a physician like Paul, had a long-running dispute with the senator.

Milliken said Boucher’s $7,500 bond requiring him to keep a distance of at least 1,000 feet (305 m) between himself and Paul remained in effect.

Earlier this week, U.S. Senate Republican leader Mitch McConnell said Paul would return next week.