Someone thought they saw him down by Waikanae River in the area of the estuary, Pryor said.
"We've been in touch with whitebaiters down there to see if they saw anyone swimming in the water or anything like that."
Police did not respond to questions about the potential new sighting.
Pryor said he had no idea where his dad would have gone to.
"What is most plausible to us is he was walking to a job, maybe it was a job sort of nearby, and he just got trapped somewhere.... we've had people searching all over Waikanae and door knocking."
Almost 5,000 people are now following a Facebook page created to help with the search effort.
"The community has been fantastic," Pryor said.
"We've had an overwhelming response to all this."
He said Facebook was the best point of contact if anyone wanted to get in touch with the search party or help out.
The page said Joe Pryor had walked from Metco Engineering on Omahi St towards Ngaio Rd.
He was wearing blue overalls, and later an orange and white bucket hat along with a TravelMarvel backpack.
Police said he is about 178cm tall and of a thin build.
He was spotted by a customer of his across the railway track outside the St Lukes church on Elizabeth St walking away from the tracks between 8.15am and 8.20am on Friday.
A police spokesperson confirmed they had received the report of this possible sighting.
This is currently the last known sighting of him.
He did not have his wallet on him and his car has been searched.