Just three weeks ago, the koala - called Koori - was dehydrated and underweight. He also had an infection.

Staff tried to match him with another koala to act as his mum. He seemed reluctant to accept her at first.

But now the tiny creature - still small enough to fit into the palm of an adult's hand - is beginning to chomp eucalyptus leaves.

Koori was removed from his mother Jolie's pouch in mid-September, when he was just over six months old.

Koalas normally only begin to venture outside their mother's pouch at between seven and nine months old.

Rash

Staff at Taronga Zoo in Sydney noticed Jolie had developed a rash and realised her health was beginning to deteriorate, so vets recommended moving Koori.

A member of staff said that he's now making a good recovery.