The three white men charged with the murder of a black jogger in south Georgia have pleaded not guilty in a case that spurred an outcry across the US after mobile phone video of the shooting appeared on the internet.

Ahmaud Arbery, 25, who was killed on February 23 just outside the coastal town of Brunswick, became a touchstone in cross-country protests over racial and social justice in the country.

A former law enforcement officer, Gregory McMichael, 64, and his son Travis, 34, are charged with murder and aggravated assault.

Their neighbour who took the mobile phone video, William “Roddie” Bryan Jr, 50, was charged with murder and attempt to illegally detain and confine.

 Gregory and Travis McMichael.

Father and son Gregory and Travis McMichael have been charged with murder and aggravated assault.

The New York Times.

Police say Gregory McMichael saw Arbery jogging through his neighbourhood outside of Brunswick and believed he looked like a burglary suspect.

The elder McMichael called his son and the two armed themselves and drove after Arbery.

Bryan joined the chase in his own vehicle, police say, and took video of the incident on his phone, which appears to show the McMichaels confronting Arbery before Arbery was shot with a shotgun.

Judge Timothy Walmsley accepted the not guilty pleas and waived arraignment at the request the defendants’ lawyers.

No court date was immediately set but there were several motions pending for later Friday morning on behalf of Bryan, including a request for bond.

“Keeping him in jail isn’t going to accomplish anything,” Bryan’s lawyer Kevin Gough told reporters on Thursday.

“Going in and out of jail is difficult because of the virus, and being in jail is tough with the virus,” Mr Gough said.

Gough told Reuters he also plans to ask that the state replace the lead prosecutor.