A South Australian father is due to face a bedside hearing after being charged with murdering his three-year-old son in the family car.

36-year-old David Janzow was charged with murder late on Tuesday, before being taken into surgery at the Royal Adelaide Hospital for a neck wound which police say was self-inflicted.

Police are expected to interview him on Wednesday.

A post-mortem is also due to be conducted on Wednesday on the boy, who police say suffered injuries consistent with multiple stab wounds.

The boy’s mother rang police on Tuesday morning saying her husband had taken their son from their Stepney home and she had concerns for their welfare.

Soon after, Jansow drove up to an unrelated crash scene at Athelstone, telling police his son was injured.

Superintendent Graeme Adcock said the man’s black Volkswagen Amarok has been impounded by police.

“We’re fairly confident the actual vehicle was the actual crime scene,” he said.

He said it was too early to say whether mental health issues were involved in the tragedy.