The Chinese buyer of A Noble Relic would have to ask permission to take it out of New Zealand.
He did not want to comment at the time about whether he would try to do so.
The revelations come a week after thieves smashed their way into a Parnell gallery and stole two Gottfried Lindauer paintings valued collectively at nearly $1 million. Police are still trying to track down the paintings and catch the culprits.
Ngati Manawa elder Pem Bird told Fairfax if he was a descendant of a Goldie portrait's subject he would not want it to leave the country.
"This is a classic example of two cultures clashing. I would venture to suggest that if my people knew that was going to be the outcome they would not have agreed for themselves to be painted. It is as simple as that - if [they knew] it was to be sold to the highest bidder and to be taken outside the country."
He said he hoped the painting would not be allowed to leave the country.
"It would be great for all for our taonga to be protected."