YEREVAN, JULY 5, ARMENPRESS. A polar bear dubbed “the saddest bear in the world” has died in his zoo in Argentina, after repeated attempts to move him to better conditions failed, reports The Telegraph.

Arturo, who was the last captive polar bear in the country, died of old age in Mendoza on Sunday. He was 31.

The bear, born in the US and moved to Argentina aged eight, earned the nickname after his mate died, leaving him alone.

And he became a cause celebre for animal rights activists in 2014, when Greenpeace began a petition to have him moved to Canada. More than half a million people signed a petition demanding his move north, but veterinarians said he was too old to survive the journey.

But his case was not the only one to cause controversy in the zoo, situated at the foot of the Andes.

Last month it closed its doors to visitors after 64 animals died between December and May. Officials said outbreaks of bacteria and overcrowding were to blame.