File photo: Winner, a polar bear, breaks a decorated Easter egg containing food inside at the zoo in Buenos Aires, Argentina.

Buenos Aires - The last polar bear at the Buenos Aires zoo has died amid a heat wave.

Zoo officials say “Winner” became nervous and irritated amid the scorching heat of South America's austral summer and the noise from fireworks during Christmas Eve celebrations. This affected his ability to control his body temperature and he apparently died of hyperthermia.

The zoo is widely visited in the Argentine capital and has traditionally showcased polar bears.

Officials say the animals used to live in a 2.5-meter-in-diameter pool but their cage was improved in 1993 when a 145,000-litre pool was built along with a site for birthing and three security rings.

The zoo said in a statement on Wednesday that the site had been visited by experts and met all international regulations to house polar bears. - Sapa-AP