Man charged with father's murder

A man has been charged with murdering his father following a domestic dispute in Adelaide’s southern suburbs.

Police said the father and son had an altercation at a Port Noarlunga home just after midnight.

Officers arrived to find the 68-year-old collapsed in his doorway.

Paramedics pronounced him dead at the scene.

Neighbours said they could not believe what had happened.

"He was a really nice, genuine man who always had time to stop and talk to everybody and just a very nice, friendly man," one neighbour said.

Police haven't revealed what injuries the father and son suffered.

Forensic officers have collected vital clues from the scene.

A post-mortem will be undertaken to determine the cause of death.

The man's 45-year-old son has been charged with murder.

The lawyer for the accused said his client is determined to fight the case.