Russia has started a bizarre colonial-style scramble after a submarine planted a flag under the North Pole to symbolise the Kremlin's claim to the oil-rich Arctic.
Now, the New Zealand company that partly conceived the project says the controversy threatens to overshadow the success of the expedition.
Deep Ocean Expeditions came up with the idea to dive to the seabed at the North Pole nine years ago and brought on Russian investors about a year ago.
New Zealander Peter Batson, the company's project scientist, told the Weekend Herald from the Arctic Sea last night that the first successful dive to the ocean floor at the geographic North Pole had been an amazing trip.
He was aware of controversy over concerns the Russian flag was a symbolic bid to stake a claim to a region thought to contain vast reserves of oil and gas.
Russia had reportedly also used the expedition to gather samples to substantiate its claim that the Lomonosov Ridge, a shelf that runs through the Arctic, is an extension of Russian territory.
Mr Batson was speaking by satellite phone on board the Russian ice-strengthened ship Akademik Fedorov.
Its two Mir submersibles made the dives over 4261m beneath a thick cover of permanent sea ice.
Mr Batson, who had been taking photographs of the expedition, said it was quite a sight to see the submersibles disappear into the relatively small hole in the ice smashed open by the Russian icebreakers.
His Australian colleague Mike McDowell, the founder of Deep Ocean Expeditions, was on one of the submersibles.
Mr McDowell told the Weekend Herald it took nearly three hours to reach the seabed, which was explored for a couple of hours before the three-hour journey back.
"It was very difficult navigation to find a very small ice hole."
At one point the ship lost contact with the submersibles.
The Russian plaque listed the names of the expedition, the two submersible pilots and the date.
It had a short painted metal Russian flag attached but he thought too much had been read into that.
"I left a titanium plaque with '02/08/07, Mike McDowell, Australia', so maybe I will claim it for Australia too."
It was a privately funded expedition, with no contribution from the Russian Government.
Mr McDowell said the flat silt seabed was as expected and he saw small fish, sea anemones and tiny jellyfish.
Boris Gryzlov, leader of the United Russia Party, hailed the expedition as "a new stage in developing Russia's polar riches".
"I am proud our country remains the leader in conquering the Arctic."
International law allocates rights to the five states with territory inside the Arctic Circle - Canada, Norway, Russia, the US and Denmark (via its control of Greenland).
But Russia is claiming a larger slice because, it says, the Arctic seabed and Siberia are linked by one continental shelf.