A search of about 200 properties near the house where a Christchurch teenager was last seen has so far failed to turn up any items of interest.
Hayden Miles, 16, has not been in contact with his family since his mother pleaded with him to come home on 22 August this year.
The officer in charge of the investigation, Detective Senior Sergeant Tony Hill, says police completed a search of houses around the Cashel Street area on Friday.
A forensic examination of the house at the centre of the investigation will continue at the weekend.
Mr Hill says about 500 people have been spoken to by police and 30 staff are working fulltime on the investigation.