A dramatic three stage removal operation could theoretically be mounted to rescue the Beluga whale which has found itself splashing about in the mouth of the river Thames.

Animal welfare experts could use the same methods deployed to lift and fly Keiko - the whale which starred in the film Free Willy - to a safe sanctuary in 1993.

But for the moment Benny the Beluga will be allowed to remain in the Thames unhindered, unless it begins to show signs of ill health or distress.

With the waters of the Thames and North Sea cooling with the onset of winter scientists believe the whale will be happy where it is until spring.

Then, if necessary they could lift it in a giant ‘wet sling’, before transferring the creature to a tank and flying it 1,148 miles to a sea sanctuary off Iceland.

Here Benny could be rehomed in a 32,000 square-metre sea pen in Klettsvik Bay, in an operation that would recall the one mounted when Keiko, a 10,000-pound killer whale, was flown from an aquarium in Newport, Oregon, to a tiny coastal Icelandic island.