He said in the past, Mr Munro had sometimes hidden for three to four days before being found. Mr Were said that meant searchers had to physically find him.
Mr Were said searchers believed Mr Munro had taken his shoes off. He said they had found footprints, but nothing leading to the missing man.
The number of searchers looking for Mr Munro has been boosted to 50.
Extra staff have been brought in from Auckland, Thames-Coromandel and Tauranga. Specialist cavers are also on standby from Waitomo.
Mr Munro, and Alfred Jonakait, 53, also intellectually disabled, went missing during an IHC group outing in the bush near Te Kuiti.