Humpback whales make 'wrong turn' into crocodile-infested river in Australia's Kakadu national park

The sightings in the Northern Territory are surprising, as the whales usually migrate to Antarctica at this time of year

A humpback whale has been spotted for the first time in Kakadu's East Alligator River, and experts are concerned it may get stuck.

It is believed three whales initially entered the river and that one has remained, although it is not clear if the others have actually left or are merely staying underwater.