Global environmental activist John Varty has offered R1m to secure the freedom of three elephants at the Johannesburg Zoo.

Varty said he put in the offer on Tuesday.

"It has been agreed worldwide that elephants are not suitable for zoos. They are very social animals, they live in herds and to confine them to a small enclosure is totally unacceptable," he said.

There has been a fierce battle raging over Lammie, the female elephant at the zoo.

Lammie was alone in her enclosure from September 2018 when her partner of 17 years Kinkel died.

More than 300,000 signatures to public petitions and a letter from leading elephant management experts to break the cycle of captivity had preceded the introduction of a 22-year-old bull called Ramadiba and a 19-year-old female called Mopane to the Joburg Zoo from the Eastern Cape.