Donald Trump has defended his campaign chief, who has been charged following claims he assaulted a reporter.

Corey Lewandowski - who was has been charged with misdemeanour battery - has been accused of roughly grabbing Michelle Fields, then a Breitbart reporter, and shoving her during a Trump rally on March 8th, leaving a bruise on her arm.

CCTV pictures appear to show Mr Lewandowski pull her backwards as she tried to ask Mr Trump a question.

The Republican frontrunner in the US presidential race says his aide is a 'good person' and 'absolutely innocent'.

He told reporters that the news conference was over at the time of the incident, "and she was running up and grabbing and asking questions - she wasn't meant to be doing that".

However, Mr Trump's rival for the Republican nomination, Ted Cruz, has criticised the billionaire's campaign, arguing "there's no place in politics for insults, for personal attacks, for going to the gutter - and there should be no place for physical violence either".

Speaking to reporters yesterday, Hillary Clinton also criticised Mr Trump's campaign.

The Democratic frontrunner suggested, "as I’ve said repeatedly, what Donald Trump has been doing these last months is inciting violent behavior and aggressive behavior that I think is very dangerous and has resulted in attacks on people at his events and this charge that was brought against his campaign manager".

However, she also stressed that she was referring to the campaign generally, adding "I’m not going to comment on this particular case. The charge has been made and they deserve to have their cases heard".