A post-mortem examination has been completed on a foetus found in a Christchurch wastewater treatment plant last week, and police say there are no indications of foul play.
Police still hope to identify the mother to ensure that she has received the appropriate support and medical care.
The post-mortem examination found that the gestation of the foetus is estimated to have been approximately 18-20 weeks, a period that police say "would be incompatible with the ability to sustain life".
The matter has been referred to the coroner.
Police are appealing for the mother or any members of the public, medical profession or support groups that may have been in contact with her to please contact Christchurch Police on 03 363 7400.