The reasons range from a flow of sewage water into the deer enclosure in February to mongoose bites which caused rabies - but all of these together have claimed the lives of 16 spotted deer at the National Zoological Park in New Delhi.

The zoo has nearly 120 spotted deer in its enclosure and since the death of 16 of them, some of the rest have been vaccinated and placed in a separate enclosure.

"We have been monitoring the situation as there has been some mortality. Rabies has been detected as the cause of death," the zoo's director, Amitabh Agnihotri has said. "We are vaccinating the animals and all preventive actions have been taken. Death due to rabies is common phenomena among mammals."

It has been two years since the tragic accident led to the death of a 20-year-old at the Zoo. after being mauled by the white tiger. While the zoo has been quick in brushing the matter off, it is the Central Zoo Authority (CZA) that has taken up the matter, calling it an "epidemic". The body has demanded a report on why immediate action was not taken to curb the losses.

There is also a possibility of a similar outbreak among the sambhar deer in the zoo as well.

It is also the CZA that is probing the real reason behind the epidemic. "The chances of mongoose bite is more as we have found spaces for them to move around in the zoo. It is not possible for dogs to have interacted with the deer in the enclosure,"an official said.