That investigation was upgraded to a homicide inquiry on July 26 after police said they no longer believed she was alive.
Police undertook a forensic examination at a property for sale on Trevor St, Hornby, the last place she was seen alive.
Searches have also taken place in and around Halswell River and Lake Ellesmere.
Water levels have caused some issues for searchers, with police having to wait at times for water levels to recede so they could continue searching.
Items of interest
Police made a public plea on August 15 for a spade and clothing believed to be linked to the murder investigation.
Detective Inspector Nicola Reeves told Checkpoint investigators were seeking a grey tracksuit, a distinctive patterned sweater and a metre-long Xcel brand spade.
Reeves said they were discarded somewhere in the Christchurch area between midday on Wednesday, July 19, and 5pm on Saturday, July 22.
“Whether it’s been discarded on the side of the road or hidden somewhere, and people happen to see it on their travels, then we would like to be contacted about that.”