Bhubaneswar, May 25: An eight-year-old tigress at Nandankanan zoo today gave birth to a stillborn melanistic cub.

The zoo, which is known for its white tigers, made news in July 2014 after two melanistic tigers were born. The births had drawn national attention mainly because of the melanistic cub, a rarity.

Zoo officials said that today the dead cub was born to Renuka and Samrat, 6.

"The CCTV footage clearly shows that the cub was born dead. The cub had a large portion of black colour along with yellow," said Jayant Dash, deputy director of the zoo.

The current tiger population in the zoo is 22, including two cubs.

Zoo officials said the black tiger was a rarity and often caused by inbreeding. "The black colour is due to pseudo-melanism in which dark coloured pigment melanin is developed in the skin," said a senior forest official.

In June 2013, a rare melanistic or black tiger was photographed in the core area of the Similipal National Park in Mayurbhanj district.

The zoo authorities have been very careful after five newborns died on November 18, 2011. All five cubs were born to Priyanka, a 12-year-old tigress. It had prompted the state government to conduct a probe.

"We have kept a close watch on the health condition of the mother, but unfortunately, the cub was born dead. There is no chance of negligence," said a zoo official.

On the other hand, the zoo officials anticipate that more melanistic tigers would take birth in future.

"We were apprehending the previous incident of birth of melanistic tiger was an accident. But today's incident hints at the presence of such colour specific genes in captive tigers. The zoo will have more value in terms of animal exchange as melanistic tigers are very rare," said a zoo official.