Police investigating the killing of Wellington woman Mei Fan are trying to source witch's costumes bought in the city for Halloween two years ago.
Ms Fan was found dead in her house in the suburb of Miramar in November last year. She had been stabbed.
On Friday, investigators released a picture of a witch's hat and cape taken in 2011 and would like to hear from anyone who may still have an identical costume purchased in Wellington at the same time.
Detective Senior Sergeant John van den Heuvel said he is not suggesting that the killer wore a witch's costume as part of a disguise, but for reasons he can't disclose it is important to locate similar costumes.
Last week, police revealed that someone had placed a small red card with a religious verse next to a photo of the 37-year-old mother of two.
Police said since the forensic scene examination was completed, someone had forced entry into the house, possibly between 3 and 17 December.