Republican candidate Greg Gianfort was heard yelling "Get the hell out of here!" after a confrontation with Ben Jacobs
A journalist recorded the extraordinary moment he was 'body-slammed' by an American politician.
Montana Republican congressional candidate Greg Gianfort now faces court after police issued a citation against him for assault.
He was accused of the act against Guardian reporter Ben Jacobs on the campaign trail on Wednesday - the eve of a special election to fill the state's lone seat in the U.S. House of Representatives.
Jacobs said in a Twitter post and in a television interview on MSNBC that Gianforte "body slammed" him, breaking his glasses, at a campaign event in Bozeman.
The incident occurred as Jacobs was trying to ask Gianforte about healthcare.
Brian Gootkin of the Gallatin County Sheriff's Office confirmed a citation was issued against Gianforte for misdemeanor assault.
Gianforte has until June 7 to appear in a county court. He faces a $500 fine and six months in jail if convicted, according to Gootkin.
The sheriff added he had donated $250 to the politician's campaign in March but insisted it had no bearing on his investigation.
In a statement, the Gianforte campaign did not deny Jacobs' allegation but countered that he had instigated an altercation by barging into the candidate's office, shoving a recording device in the politician's face "and began asking badgering questions."
"After asking Jacobs to lower the recorder, Jacobs declined," the statement from campaign spokesman Shane Scanlon said.
"Greg then attempted to grab the phone that was pushed in his face.
"Jacobs grabbed Greg's wrist and spun away from Greg, pushing them both to the ground."
"It's unfortunate that this aggressive behavior from a liberal journalist created this scene at our campaign volunteer BBQ," it said.
Jacobs said he retreated to a parking lot after the confrontation to call his editor and the police.
He later spoke to MSNBC from a hospital where he was getting his elbow X-rayed.
In Jacobs' audio tape of the incident, Gianforte is heard shouting: "I'm sick and tired of you guys. The last guy who came here, you did the same thing."
After loud scuffling noises are heard, Gianforte yells, "Get the hell out of here" and demands to know if Jacobs is with the Guardian.
"Yes, and you just broke my glasses," Jacobs replies amid more shouting by Gianforte.
According to the audio tape, the confrontation began as Jacobs tried to ask Gianforte if he still supported a Republican healthcare overhaul bill after the Congressional Budget Office found the measure would cost 23 million Americans their medical insurance coverage by 2026.
A team for Fox News later confirmed Jacob's account of the incident.
Reporter Alicia Acuna said: "Gianforte grabbed Jacobs by the neck with both hands and slammed him into the ground behind him.
"Faith, Keith and I watched in disbelief as Gianforte then began punching the reporter.
"As Gianforte moved on top of Jacobs, he began yelling something to the effect of, "I'm sick and tired of this!""
Another political writer, Alexis Levinson, a reporter for BuzzFeed News, was also nearby.
"All of a sudden I heard a giant crash and saw Ben's feet fly in the air as he hit the floor," Levinson tweeted.
She said she then heard yelling that sounded like Gianforte.
She said Jacobs emerged from the room "holding his broken glasses in his hand and said, "He just bodyslammed me."
Levinson said Gianforte then went into a room with an aide and closed the door.
Gianforte, a tech executive, is running against Democrat Rob Quist, a banjo-playing political novice who hopes to pull off a surprise victory in the Republican-leaning state.
A victory for Quist could signal trouble ahead for President Donald Trump and his fellow Republicans as they defend their 24-seat House majority in next year's mid-term elections.