The Bellerby family said yesterday in a statement they were hopeful, "there being signs of life" after the sighting of significant debris.
The debris was found after a privately funded search of the Tokara Islands, a chain of 12 small islands, of which seven are inhabited.
Debris from Gulf Livestock 1 has been found on the Tokara Islands off Japan. Photo / Supplied
It included a canopy of a Viking liferaft, a life ring, a single blue boot, several dead cows, and three orange barrels strapped together.
The family, who had been helping fund the private search, said it had cost about $54,000 to date for fixed-wing flights, and $81,000 for helicopter flyovers. The money was donated.
The search by satellite would continue, and this weekend a privately funded aircraft search would be done around the Amami Islands.
Debris from Gulf Livestock 1 has been found on the Tokara Islands off Japan. Photo / Supplied
"The families are working with maritime experts to further identify the items and other potential areas of interest," they said.
All the information collected had been passed on to the Japanese Coast Guard by Australian authorities.
"The Bellerby family are calling on the New Zealand Ministry of Foreign Affairs for official diplomatic support with the Japanese Coast Guard while the window of survivability remains possible."
Debris from Gulf Livestock 1 has been found on the Tokara Islands off Japan. Photo / Supplied