A man has appeared in a Mildura court charged with murder after a man's was found in South Australia's south-east on Tuesday.

Keith man Jordan Campbell, 20, was arrested in Robinvale south-east of Mildura on Wednesday night.

Police later charged with him with the murder of 23-year-old Navarone Hutchins, also from Keith.

Mr Hutchins, who worked as a courier for a Mount Gambier company, was last seen as he left a friend's house on Friday night.

Police say he was heading for a local hotel but never arrived.

A State Emergency Service volunteer discovered the body on a dirt track about six kilometres outside the town and police say it shows signs of severe head injuries.

Campbell appeared in the Mildura Magistrates Court today.

He has been remanded in custody and will reappear in court tomorrow when South Australian detectives are expected to apply for his extradition.

Police have continued to interview people in Keith and say they have seized security vision.