He would not say whether the body had been found wearing a life jacket.
Mr Fergus said the search currently involved the Navy, Coastguard, Westpac Rescue Helicopter and the Harbourmaster.
He would not share the identity of the body but said family had been told.
"We have discussed all our findings with them."
The 14-foot fibreglass dinghy left Martins Bay in the Mahurangi Peninsula, Auckland, around 5pm last night with two fishermen on board, but did not return.
Police this morning confirmed that debris belonging to the missing boat had been found.
Photo / Sophie Ryan
Inspector Mark Fergus, relieving area commander for Rodney, said the two missing men were from Warkworth.
One is aged in his mid-20s and the other mid-30s.
He described them as regular fishermen and friends.
"[The family] is in shock. They're worried and scared for their loved ones."
He said a number of people had joined the search from the community.
"In a small community like this everyone knows everyone."
He urged anyone who had been out in the water in the Kawau Bay area and had seen the 14-foot red fibreglass boat to tell police.
Martins Bay was a popular spot to launch boats, Mr Fergus said.
The pair launched the boat around dusk and were expected to be back around 10pm, but when they didn't return their families raised the alarm.
Photo / Sophie Ryan
It was believed the two men were heading out to Maori Rock for an evening fish, the coastguard said.
Their car and trailer remained at Martins Bay this morning.
Friends of the fishermen had been volunteering to assist in the search and he encouraged any boaties in the area to call coastguard if they saw anything out of the ordinary.
The Westpac Rescue Helicopter and a police Eagle chopper have also been scouring the area for the boat today, alongside the Navy, Coastguard and the police maritime unit.
Anyone who was fishing in the area last night or who saw the vessel it asked to contact Warkworth police on (09) 425 8109.
- additional reporting Anna Leask
