An Icelandic whaling company has been accused of slaughtering an endangered blue whale in a "deplorable act", provoking anger and condemnation from the international marine conservationist community.

Animal rights campaigners who photographed the whale’s carcass, say it was harpooned and killed off the west coast of Iceland on July 8.

Genetic sampling has been conducted to establish the species of the whale, with experts unable to rule out the possibility it could be a rare blue/fin whale hybrid.

Kristján Loftsson, the multi-millionaire CEO of Hvalur hf whaling company, told the Telegraph he was “pretty confident” tests would confirm the animal was a hybrid species and not a blue whale.

“This whale, when you see it swimming in the ocean, it was like a fin whale,” he explained. “There were no characteristics of a blue whale, it is very easy to tell a blue whale in the ocean.

“They go after it as a fin whale. When they shoot it and take it alongside the vessel, they noticed the ventral grooves, which you don’t see when the whale is swimming in the ocean. This is what we have had with other hybrids in the past.

“It is like a fin whale, it behaves like a fin whale, but after you shoot it you notice [the characteristics] are different to a fin whale.