The New Zealander on a yacht making an unsanctioned trip to Antarctica is reported to have planted a Mana Party flag in the polar ice.
The man was discovered onboard the Nilaya after it left Auckland in a hurry on January 23.
The yacht reached Antarctica earlier this week.
Norwegians Jarle Andhoy, 34, and 19-year-old Samuel Massie, are leading an expedition to try to find the wreckage of the Berserk II, which sank in McMurdo Sound in February last year, killing three on board.
That yacht was a supply vessel for an attempt by Mr Andhoy and Mr Massie to reach the South Pole on quad bikes.
The Herald on Sunday reports that the New Zealand man, 53-year-old South Aucklander Busby Noble, deliberately joined the trip and was not a stowaway.
He is said to be an acquaintance of one of the three men who died on Andhoy's last Antarctic expedition.
Mana Party candidate Kereana Pene said he spoke to Noble by satellite phone this week.
When he arrived on the continent, Mr Noble planted a Mana Party flag he had taken with him in the ice.
Mr Noble has been in contact with the Ministry of Foreign Affairs and Trade (MFAT) and has said he is OK.
MFAT says it will remain in contact with the man's family members and monitor the situation.
NZN