US Republican presidential front-runner Donald Trump's campaign manager Corey Lewandowski has been charged with battery in Florida after allegations that he forcefully grabbed a journalist at a campaign event.             

Police in Jupiter, Florida, charged Mr Lewandowski with intentionally grabbing and bruising the arm of Michelle Fields, a reporter at the time for news outlet Breitbart, when she tried to question Mr Trump at a campaign event on 8 March.             

"Mr Lewandowski is absolutely innocent of this charge," Mr Trump's campaign said in a statement.

"He will enter a plea of not guilty and looks forward to his day in court. He is completely confident that he will be exonerated."             

Police released a video showing the incident.

It shows Ms Fields walking alongside Mr Trump, and Mr Lewandowski grabbing her arm and pulling her backward as she tries to question the Republican candidate.

Previous videos of the incident had been obscured by people in the crowd.

Campaign rallies for Mr Trump have been marked by rowdiness and occasional physical contact between protesters and supporters or security personnel.

Mr Lewandowski was charged with simple battery, defined under Florida law as intentionally touching or striking a person against their will.

For a first offence, it is a misdemeanor in the first degree, which carries a maximum sentence of one year in prison or a fine of $1,000.

A court date was set for 4 May, according to the police report.

Jupiter police said Mr Lewandowski turned himself in to police, and he was issued a notice requiring him to appear in court and then released.

Mr Lewandowski's lawyer declined to comment on whether his client would step down as campaign manager.

Mr Lewandowski had previously claimed on Twitter that he never touched Ms Fields, calling her "delusional" in a post on 11 March and denying that he had ever met her.

Mr Trump said at the time that he was told nothing had happened at the event, and said the incident was "in my opinion, made up".

Ms Fields resigned from Breitbart less than a week after the incident, citing what she said was the online news outlet's refusal to stand behind her amid the allegations.