The New Zealand Defence Force says it's difficult to know whether it would have found the 29 Taiwanese fishermen missing in the ocean off Kiribati if it had been asked to join the search earlier.
The 14-strong crew of an Air Force Orion searched for signs of the men for 30 hours over a three day period, but New Zealand's involvement in the search ended on Sunday.
The burnt-out Taiwanese fishing boat was found drifting abandoned off the Phoenix Islands on November 9, but New Zealand was only asked to help last week.
It is thought the 29 crew of the Ta Ching 21 may have made it onto three liferafts that were missing from the fishing boat.
A US Air Force C-130 searched without success, and the RNZAF was alerted last week.
There has been no sign of the three life rafts thought to be carrying the men.
Squadron leader Glenn Davis says the Air Force Orion will return to New Zealand on Monday, remaining on two-hour standby in case further requests for help are made by Fiji's search and rescue.
Mr Davis says there's no guarantee the Air Force getting involved earlier would have led to the men being found.
Squadron leader Davis says New Zealand's role has ended because after a thorough aerial search, there was nothing further the crew could do.