Police officers investigating a fatal stabbing on Waihi Beach want to talk to a person who handed over a knife to a security guard.
Robert Wilkinson, known to his family as Murray, was stabbed outside his caravan on New Year's Day, and died later in hospital.
Detective Inspector Chris Page says someone handed a knife to a security guard at the scene of the attack on Thursday but the guard failed to take their contact details.
Mr Page says the person did the right thing but they want to speak to them further to find out where and how the knife was found.
He says they don't yet know if the knife was the murder weapon.
Police have stepped up their investigation into the murder of the New Zealander, who was on holiday from Queensland.
He died in Waikato Hospital on Thursday from injuries suffered after being stabbed the face and neck.
Forty officers from the Waikato, Bay of Plenty and Counties Manukau districts are working on the case as well as members of an Auckland-based specialist search group.
Despite the knife being handed over on Thursday, on Friday police extended their search for the weapon used in the attack, canvassing rooftops as well as going door-to-door.
Detective Inspector Chris Page says anyone who finds something unusual on their property such as clothing or a potential weapon should leave it where it is and contact police.
Mr Page says the results of a post-mortem will not be made public until further forensic examinations have been completed.
Appeal for photos
Chris Page says photos taken by holidaymakers, many of whom are in their teens and will have already left the area, could provide the pieces to the jigsaw needed to find the person responsible.
Mr Page urged parents to talk with their children to find out if they had taken any photos while in the area - particularly involving groups of people out and about at night time - and to give them to police.