Woman's death in SA unexplained

The position of a woman's body in the backyard of her home in South Australia's southeast has stopped police from declaring her death came from natural causes.

Pauline Calvett, 72, was found by a neighbour on Easter Sunday with a post mortem examination failing to determine the cause of death.

Detective Inspector Greg Hutchins says it's most likely Ms Calvett died of natural causes but police are just concerned about the position her body was found in.

Without providing more details, he said there could be an explanation but inquiries were continuing.

"We need to identify her movements, to try to have a better understanding of her," Det Insp Hutchins told reporters on Tuesday.

"More likely than not she probably died of natural causes, but there are some aspects which we don't totally understand or can't explain."

The last known sighting of Ms Calvett was on March 17 when she pulled in to the driveway of her home.

Her car remains at the Bowman Street address, with her body found by a neighbour at about 3.40pm on March 27.

A search of her home has since turned up her keys and purse, which were originally thought to be missing.

Insp Hutchins said it was likely Ms Calvett died on or about March 17, given the decomposition of her body.