The sightings were made during a research cruise off Kamchatka by a group of Russian scientists and students, co-led by Erich Hoyt, the long-time orca scientist, conservationist and author who is now a senior research fellow with the Whale and Dolphin Conservation Society (WDCS).
"We've seen another two white orcas in Russia but they've been young, whereas this is the first time we've seen a mature adult," he told BBC News.
"It has the full two-metre-high dorsal fin of a mature male, which means it's at least 16 years old - in fact the fin is somewhat ragged, so it might be a bit older."
Orcas mature around the age of 15, and males can live to 50 or 60 years old, though 30 is more commonplace.
"Iceberg seems to be fully socialised; we know that these fish-eating orcas stay with their mothers for life, and as far as we can see he's right behind his mother with presumably his brothers next to him," said Dr Hoyt.
The cause of his unusual pigmentation is not known.
They didn't name the orca Moby Dick as you would expect, but instead it is called Iceberg, perhaps because of the recent anniversary of the Titanic incident. Link -via reddit
(Image credit: E. Lazareva/Far East Russia Orcas Project)