Police are asking people to review any home-based CCTV footage as they head into the fifth day of searching for Dunedin man Gordon Mclean.
The 63-year-old, who has dementia and schizophrenia, has not been seen since he left Wakari Hospital on Thursday.
Yesterday police released an image of slippers similar to those worn by Mr Mclean in a bid to elicit public help.
Southern District Health Board mental health, addictions and intellectual disabilities directorate medical director Dr Brad Strong said the board would review how Mr Mclean was able to disappear from the hospital.
"He is frail and in need of medical support, and we're very concerned for his safety and well-being.
"As with any serious issue, we will be reviewing the circumstances surrounding this matter.''
Extensive searches of Wakari, Frasers Gully, Halfway Bush and Helensburgh by police, LandSAR, volunteers and search dogs had failed to find any sign of Mr Mclean.
Search and rescue co-ordinator Sergeant Richard Panting asked the public to look for signs of the missing man.
"Even if you find something you don't believe would be of interest, please still take the time to contact us - it could be just the piece of information we need.''
