Acting Detective Inspector Tim Williams said a post-mortem examination of the body has been completed.
Police have not yet been able to identify the victim, saying only that she was a female, middle-aged and of Asian descent. The woman was about 160cm tall.
Williams dismissed any speculation the woman was Yanfei Bao, a real estate agent who went missing in Christchurch on July 19 last year.
But police have today released pictures of patterned blue pyjama bottoms and an emblem on a singlet the woman was wearing when her body was found.
Once police identified the body, they would then tell the woman’s next of kin of her death, he said.
“The Government is committed to keeping all New Zealanders safe and secure.”
Williams said the investigation was complex, as police were still trying to work out why, when and where the woman died.
“We’re continuing to treat this matter very seriously and we’re determined to hold the person or persons accountable for this death.
There was no wider risk to the public, he said.
“If there’s a woman in your community who matches this description that you haven’t seen for a while or have concerns about, please make contact with the investigation team.”
He said people had already come forward with CCTV footage and other information.
The woman was wrapped in black plastic rubbish sacks, Williams said.
He would not speculate on whether the offender had remained in the country.
“We’re keeping an open mind to all avenues of the investigation,” he said.
“It is complex because we don’t know who she is,” Williams said.
Police yesterday said the person found floating inside black bags near the shoreline of Gulf Harbour Marina was a small woman of Asian descent.
The discovery of the body was initially treated as unexplained before police upgraded it to a homicide investigation.
Police appealed for information about the mystery woman and asked anyone who had been in the area in recent days and may have seen something to come forward.
Yesterday, Williams said police were still unsure of the circumstances surrounding the woman’s death and would not speculate.
“At this stage, we have not been able to confirm the identity of the victim, but we can say they are a female of Asian descent, possibly Chinese, and small in stature.
He hooked it and pulled it into the shore - it was heavy but he managed to pull it up the rocks a little.
“I took the hook out and thought, ‘Right, let’s see if it’s a bag of rubbish and I need to dump it in a rubbish bin or something’.”
There was “a bit of clothing ... and then there was this hand sticking out”.
It was at that point that he called police.
“Two cops turned up and they thought I’d actually said there’s just a hand in a bag and then they went down there and went, ‘Oh no we’ve got a body’,” Middleton said.
Police have urged anyone with information to contact police on 105 or go online using the ‘update my report’ function and use reference file number 240312/9837. Alternatively, information can be provided anonymously via Crime Stoppers on 0800 555 111.
The community can contact police on 0800 755 021 to speak directly to the investigation team.