Charges over cold case murder of SA man Jayson Doelz

Three men and a woman have been charged over the cold case murder of a South Australian man.

Jayson Doelz was bashed and stabbed and his body dumped at Kersbrook, in the Adelaide Hills in January 2012.

The breakthrough comes a month after a 9NEWS report revealed the investigation had taken police to the far north town of Innamincka, where they believe the black Ford XR6 used to abduct the young father had been buried under a shed.

"I can't go into the motive other than to say that this murder arose as the result of a very, very, very minor matter," Det. Supt Des Bray said.

A Moonta man, 26, Northfield man, 29, and Ingle Farm man, 31, have all been charged with murder.

An Ingle Farm woman, 28, has been charged with assisting the men charged with murder.

All four will appear in the Adelaide Magistrates Court on Monday.