RNZ reports the 40-year-old man and his 14-year-old son from 'Eua went on a fishing trip on Saturday 10 December.
The pair were in a 14ft boat and left about 5:30am local time.
Tonga Police said they last made contact by mobile phone on Saturday evening advising of engine problems.
A Marine Search and Rescue operation was launched but was unsuccessful prompting police to request help from New Zealand.
A Royal New Zealand Airforce Orion left New Zealand at 9am and has found the missing fishermen.
Photo by NZ Defence Force
