Friday, September 4, 1998 Published at 15:37 GMT 16:37 UK
'Willy' the whale nears freedom
Keiko, the star of Free Willy, has to learn to fend for himself before he can be freed
He was captured at the age of two and has spent most of his life performing for audiences in the Reino Aventura amusement park near Mexico City.
He developed skin lesions, flabby muscles, became prone to viruses and at 3490kg was a tonne underweight.
A foundation - partly funded by the makers of the film - paid for him to be shipped to an aquarium in Oregon in the US for rehabilitation two years ago.
"It's been a very speedy recovery," said Diane Hammond of the Free Willy Foundation.
"When we first saw him we thought it would take a great deal of work and time to get him anywhere close to what he is now."
Having spent so long in captivity, he has had to re-learn natural behaviour like catching fish for himself - something that has never been done before.
On 9 September he will be picked up in a sling and flown to his new home in Iceland, where scientists will observe him until they are sure he can survive in the wild.