A fishing rod identified as belonging to the missing fisherman was found on Tirohanga beach.
"Given where the items have been found so far, there is concern the fisherman's boat may have been submerged," Forsyth said.
"Our thoughts are with the family at this difficult time."
The search has been suspended for the weekend but Forsyth said efforts are expected to continue next week, with a further sweep of the area planned depending on weather conditions.
Earlier today, Kauta's niece Mia van den Broek said Thursday's discovery of the chilly bin had brought mixed emotions to his whānau.
"I'm relieved that something of his has finally been found but sad because of the harsh truth I've told myself."
Van den Broek said it was a struggle but she needed to be grateful for the amazing times she and others had shared with her uncle.
"There's still hope in finding him though, this is just the beginning of him coming back to his home on land, as the sea was his home," van den Broek said.
Police continue to appeal for members of the public to report any items of interest which might wash up on the shoreline, between Tōrere and Maketu.
A red tote fuel container, more rods, wooden oars, and a yellow lifejacket remain missing.
Anyone who comes across any of the items of interest is asked to contact police on 105, quoting file number 220418/0391.
