The King of Tonga is selling his mansion in Epsom - but there will be no open-home shows unless you are a serious buyer.

Siaosi George Tupou V has put his Auckland residential property, on a 1.58ha block of land, up for sale.

The hidden property, down a private driveway at 183 St Andrews Rd in Epsom, is near the Landscape Rd intersection and John O'Brien, a Bayleys agent in the Viaduct on the commercial sales team, is advertising it as exceptional.

But which suburb the place is in appears to be up for debate.

QV lists the property as being in Mt Eden. Auckland City says it is in Royal Oak, and Mr O'Brien says it is in Epsom.

QV lists it as owned by "His Majesty King George Tupou V, of the Kingdom of Tonga, His Heirs and Successors" and says it has a capital value of $8.9 million - $6.8 million for the land and $2.1 million for improvements, or buildings.

It lists improvements as two buildings, three houses, two garages and a carport.

The property is known as "Atalanga" and was bought by Queen Salote Tupou III for Tongan scholarship students.

Bayleys yesterday said the firm had been given "official instructions from the King" not to speak about anything to do with the property, unless it was to a serious buyer.

But a Ray White real estate agent said it was possible it could fetch up to $10 million.

Rita Lan, who sells lavish properties in Remuera and Epsom, said it was possible the capital value ($8.9 million) might be less than the property was worth.

"It depends. I haven't seen the property but it is possible that it could be worth more than that."

Ms Lan said the fact that it belonged to royalty could also play a huge part in bumping up the price.

"Because it's the King's house,you might get more interest.

"A lot of people are like that - they'll like a property more because of a person who has lived there."

Mr O'Brien is promoting it as sunny, private and well maintained on a near-flat site in a prime location, large residence plus three accommodation blocks, a rare opportunity to create your requirements, zoned residential 2B.

Bayleys spokesman Scott Cordes said that his firm was under strict instructions to refer any inquiries about the property to the King's Auckland lawyer Nicholas Fisher.

"We would love to have done a PR campaign and show you around it but we are under strict orders," he said.

One source close to the deal said security was now in place and rubber-neckers were not welcome.

Only those deemed genuine buyers would be shown around.

Auckland City's property information database shows it incurs annual rates of $28,218.85.