A humpback whale has found its way back to the sea after losing its way in a crocodile-infested river in northern Australia.
Earlier this month, three whales took a wrong turn and ventured deep into East Alligator River in the Northern Territory's World Heritage-listed Kakadu National Park.
A group of sailors first spotted the lost trio on September 2 more than 12 miles from the river mouth.
The last of the three whales managed to navigate its way through the shallow channels and back into the Van Diemen Gulf over the weekend, Kakadu National Park manager Feach Moyle said.
"It made its way out on the high tides and we're pleased it appeared to be in good condition and not suffering any ill effects," Moyle said.
Humpbacks follow the western Australian coast in their annual migration from the tropics to Antarctica, and Northern Territory government whale and dolphin scientist Carol Palmer said it was a mystery why a whale would stray so far up a shallow river full of crocodiles.
"It could have been chased up by some big sharks or maybe it was just a wrong turn," Ms Palmer said.
Despite the river's name, there are no alligators in Australia.
It was named after the river's many crocodiles by European explorers who apparently could not tell the difference.
Authorities thought the whale was too big to be attacked by crocodiles, unless it became weak or sick.