The first all white adult killer whale has been spotted by scientists off the coast of Kamchatka in eastern Russia.
The male, which has been named Iceberg, lives in a pod with 12 family members and is thought to be at least 16-years-old given the size of his two metre dorsal fin, Erich Hoyt, co-director of the Far East Russia Orca Project, told AFP news agency.
The whale was first spotted by researchers from the universities of Moscow and Saint Petersburg in August 2010 near the Commander Islands in the North Pacific.
Hoyt said the scientists decided to "hold back on releasing photographs of Iceberg until they were able to study him further" but they have been watching him ever since, according to AFP.
Two other white orcas are known to live in the waters where Iceberg was spotted but they are both juveniles.
The scientists hope to establish whether Iceberg is an albino, a genetic condition which leaves animals unable to produce melanin, a dark pigment of skin, hair and the eye's retina and iris.
Many albino animals never grow into adulthood as their visibility poor is a disadvantage in the hunt for food and protection against predators.
Hoyt told AFP: