Police and Search and Rescue volunteers will continue their search this morning for an elderly dementia patient who went missing while visiting Waikato Hospital on Sunday.
Trevor Smith, 70, walked away from Waikato Hospital around 5pm and since then his family members have been searching for him without success.
He suffers from mild dementia and type 2 diabetes.
Search Controller, Constable Ross Moratti, said police were very concerned for the safety of Mr Smith.
''Mr Smith suffers from type two diabetes and has mild dementia and searchers and his family are concerned he may be quite disoriented due to a lack of insulin which he must take daily,'' he said.
Mr Moratti said Mr Smith was not a patient at the hospital but was visiting friends with relatives at the time he went missing.
Police and hospital staff were working to review security camera footage to try and determine his direction of travel.
"Family members continued searching for him through the evening and raised the alarm with police who briefed on duty staff about his disappearance and also mobilised Land Search and Rescue teams who continued the search until about 2am today.
"We are currently briefing with a view of putting fresh teams out in the field at first light to resume the search. At the same time we are asking anyone who might see a disoriented elderly man to check if they need help and confirm their identity."
Mr Smith was described as clean shaven with a number one haircut and of average to solid build.
When last seen Mr Smith was wearing a distinctive lime green Vodafone Warriors rugby league jersey, dark blue track-pants, plain white sandshoes and a grey cap.
Mr Moratti asked for anyone who believed they have seen Mr Smith, or who encountered someone who may be disoriented or in distress, to contact Police on 111.