Auckland’s skies saw a flash of grandeur as the world’s most luxurious private jet touched down for a mysterious whistle-stop visit in the City of Sails.

The Sultan of Brunei’s ultra-luxurious private Boeing 747-400, known as the “Floating Palace” and widely considered to be one of the most extravagant aircraft in the world, arrived in Auckland as part of an international flight route before swiftly departing.

RadarBox showed the jet touched down in Auckland at 3.11pm from Bandar Seri Begawan in Brunei, before departing at 5.18pm.

Interior of the Boeing 747 jumbo jet owned by the Sultan of Brunei.

The Sultan Hassanal Bolkiah has held his position as ruler of Brunei for more than five decades and is one of the world’s last remaining absolute monarchs.

His wealth is estimated at between $20 billion and $40b, and he is the world’s longest-reigning monarch and longest-running head of state.

In March this year, Prime Minister Christopher Luxon tweeted a photo with Bolkiah while at the Australia-Asean special summit in Melbourne.

The Sultan was known to own 11 properties in Auckland’s Herne Bay, which he sold in 2005 for $35 million, the biggest single residential real estate transaction in New Zealand at the time.

The custom-built jet is valued between $260m and $400m, with an additional $120m reportedly spent on luxury upgrades.

Some of its more luxurious features include gold-plated fixtures, Lalique crystal accents, a formal dining room with custom tableware, and a conference room.

Photo / Kevin Hacket

Other amenities include a private office, a master bedroom with en suite bathrooms, and multiple lounge areas, all crafted to offer a regal in-flight experience.

The Sultan is known to own a fleet of aircraft, including a Boeing 767-200, an Airbus A340-200, and Sikorsky helicopters.

He also owns the world’s largest private car collection, of more than 7000 vehicles, as well as the biggest Rolls-Royce collection in the world and the world’s most expensive royal car, a Silver Spur II Rolls Royce, which he plated in 24-carat gold for his wedding day.

Photo / Kevin Hacket

This “Flying Palace” allows for long-haul journeys with ease, as it includes extra fuel tanks, extending its range to more than 15,000km.

It is possible the Sultan is now winging his way to Peru for this week’s Apec summit, which Luxon will also attend.