, pleading his case in a Tweet addressed to the Argentine president, writing: “Don't cry for me Argentina? 

“No tears of Mrs Christina Fernandez de Kirchner for tortured polar bear Arturo. 

“Your hands are stained with his blood when he dies.”

The singing legend has not yet made a statement on Arturo’s death but social media was abuzz with comments from animal welfare campaigners when the news of his death broke. 

Arturo was often seen lying flat out in his concrete enclosure

“Captivity killed another living soul - Arturo, the saddest polar bear ever, passed away…” wrote one campaigner. 

Another added: "So, so sad to hear that Arturo the polar bear has died after years of suffering. He will suffer no more.” 

Last year an update on Arturo’s conditions was given by the highly respected conservation group, Polar Bears International. 

It explained how Mendoza Zoo had recently allowed Dr Don Moore, an expert from the Smithsonian Institute, to examine Arturo and spend several days observing his diet, care routines and interaction with his keepers.