Thirty tiger cubs have so far perished at the Dehiwala Zoo during the last four years. Four Bengali Tiger cubs died yesterday.
Five Bengali Tiger cubs were born on Saturday. One is alive. It is also in a critical condition, zoo officials said.
Previously 26 tiger cubs including 10 rare white tiger cubs had died at the zoo, sources said.
Last year, a rare white tiger cub was given euthanasia because he was considered abnormal.
A veterinarian told The Island that those involved in Animal Exchange Programmes should be questioned why the pedigree of an animal was not traced.
The Zoo, tagged as one of the best in South Asia, in its 78 years of operation, has lost more baby animals than any other Zoo in the region.
The last rare white tiger cub born on June 21, 2013 received special medical care due to its condition.
The white tiger had been identified as a endangered species and there were only 2,000 of them living in the world and therefore the birth of a white tiger cub was a very special and rare occurrence, an official added.
The Director General of the zoo was not available for comment.