Conservationists have described as “remarkable” a journey made by a pod of killer whales from the icy seas off Iceland to the comparatively balmy waters around Sicily.

The orcas have astounded researchers by making the epic 4,000-mile odyssey from the North Atlantic to the Mediterranean in just a few weeks.

Although distributed across the globe, the species favours cold waters and sightings in the Mediterranean are rare, apart from a small population that lives around the Strait of Gibraltar.

It is not known whether the pod is disorientated, simply following prey, or is on the move for some other reason.

Starting their journey in November, the pod is believed to have left the coast of Iceland, swum down the east coast of Britain, through the English Channel and then past Spain and Portugal to the Strait of Gibraltar.

The five orcas were spotted off Genoa in early December, becoming local celebrities.  Their dorsal fin markings were recognised by researchers in Iceland, who know the adults as Riptide, Zena, Dropi and Acquamarin.

After lingering off the coast of Genoa for more than two weeks, the killer whales then proceeded south along Italy’s Tyrrhenian coast towards Sicily.

They are now in or around the Strait of Messina, which divides Sicily from the toe of the Italian boot, where they have been spotted by fishermen.