The male giraffe was brought on February 24 for mating with the lone female giraffe 'Khusi' here at Nandankanan.
State Forest and Environment minister Bikram Keshari Arukha directed the PCCF (wild life) to probe the premature death of the animal.
The five-year-old 'Joy', which took birth at the Alipore zoo, was brought here under the supervision of an eight-member expert team headed by Assistant Director of Nandankanan Dr Kamal Lochan Purohit.
The four big cats comprising two females and a male white tiger, were transported to Alipore zoo for getting the male giraffe under the exchange programme.