A post-mortem examination determined that the baby whose body was found at Wairau Bar last month was stillborn. Police announced the cause of death on Monday afternoon.
Inspector Simon Feltham, Marlborough Area Commander, said police "are still urgently appealing for the family of the infant to come forward, as we are concerned for the welfare of the mother.
"We would like to ensure she is safe and can receive any appropriate treatment or support. We would also like to discuss options with them around the baby’s remains."
He asks anyone with information to call 105 or click onto 105.police.govt.nz (reference file number 260519/9172).